These Mango Curd Protein Bars combine a buttery shortbread crust with creamy mango curd and a raspberry swirl. A quick high-protein dessert perfect for picnic or meal prep.

Ingredients

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Instructions

Step 1

Preheat your oven to 350°F (175°C). Line a 9×9-inch baking pan with parchment paper, leaving overhang on two sides for easy removal. This is crucial because the bars are delicate when warm, and the parchment sling lets you lift them out cleanly without breaking the shortbread crust. In a food processor, combine the flour, sugar, and salt. Pulse a few times to blend. Add the cold butter cubes and pulse until the mixture resembles coarse meal with pea-sized butter pieces. Do not over-process; those tiny butter lumps create steam pockets during baking, resulting in a tender, flaky crust. If you don’t have a food processor, use a pastry blender or your fingertips to work the butter into the flour until crumbly. Transfer the mixture to the prepared pan and press firmly into an even layer. Use the bottom of a measuring cup to compact it well—an uneven crust will lead to a soggy bottom. Bake for 15-18 minutes until the edges are lightly golden and the center is set but not browned. The crust will continue to cook slightly after removal. Let it cool on a wire rack while you prepare the curd.

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Step 2

While the crust cools, make the mango curd. In a medium saucepan, whisk together the mango puree, eggs, sugar, and lemon juice until smooth. Place the saucepan over medium heat and cook, stirring constantly with a silicone spatula or whisk, until the mixture thickens and coats the back of a spoon, about 8-10 minutes. The curd should reach 170°F (77°C) on an instant-read thermometer to ensure the eggs are safely cooked without scrambling. Do not boil or the eggs will curdle. You’ll know it’s ready when the mixture leaves a clear trail when you drag your spatula across the bottom of the pan. Remove from heat and immediately stir in the butter until melted and fully incorporated. Then whisk in the protein powder until the curd is smooth and lump-free. If using plant-based protein, sift it in to avoid clumps. The protein powder adds a subtle richness and boosts the protein content to about 8g per bar. Let the curd cool for 10 minutes, stirring occasionally to prevent a skin from forming.

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Step 3

For the raspberry swirl, in a small saucepan, combine the raspberry puree, water, and cornstarch. Whisk until the cornstarch dissolves. Bring to a simmer over medium heat, stirring constantly, until the mixture thickens to a syrupy consistency, about 2-3 minutes. Remove from heat and let cool slightly. The cornstarch helps the swirl hold its shape in the curd without bleeding into a muddy mess. If you prefer a seedless swirl, strain the raspberry puree through a fine-mesh sieve before cooking. Set aside.

Step 4

Pour the slightly cooled mango curd over the pre-baked shortbread crust. Spread it evenly with an offset spatula. Then, drop small spoonfuls of the raspberry mixture over the curd—about 8-10 dollops. Use a toothpick or skewer to gently swirl the raspberry into the mango curd, creating a marbled pattern. Do not over-swirl or the colors will blend into a single pinkish hue. A few figure-eight motions are enough to create beautiful ribbons. Bake the bars at 350°F (175°C) for 18-22 minutes, until the curd is set around the edges but still slightly jiggly in the center. The center will firm up as it cools. Overbaking will cause the curd to crack and become rubbery. Let cool completely in the pan on a wire rack, then refrigerate for at least 2 hours (or overnight) before slicing. Chilling makes the curd firm enough to cut clean squares. Use the parchment sling to lift the slab onto a cutting board, and slice into 16 bars with a sharp knife, wiping the blade between cuts for neat edges.

For best results

  • For the best mango flavor, use ripe, fragrant mangoes. Ataulfo (honey) mangoes are ideal because they are naturally sweet and have a smooth, non-fibrous texture. If mangoes are out of season, high-quality canned mango puree (unsweetened) works well—just be sure to drain any excess liquid. Avoid mango juice or nectar, as they contain added sugar and lack the thick pulp needed for a rich curd.
  • Cold butter is non-negotiable for the shortbread crust. If the butter softens before baking, the crust will spread and become greasy rather than tender. Keep the butter in the fridge until the last minute, and if your kitchen is warm, chill the flour mixture for 10 minutes before pressing into the pan. You can also freeze the crust for 15 minutes before baking to ensure the butter stays solid.
  • When cooking the mango curd, patience is key. Whisk constantly and use medium heat—not high—to prevent the eggs from curdling. If you see any small lumps forming, immediately remove the pan from heat and whisk vigorously to smooth them out. Straining the curd through a fine-mesh sieve after cooking is a foolproof way to guarantee a silky texture, though it's not necessary if you whisk diligently.
  • Protein powder can be tricky in baked goods because it can make the curd grainy or dry. Whey protein blends more smoothly, but if you use plant-based, opt for a vanilla-flavored one to complement the mango. Sift the powder into the curd and whisk until completely dissolved. If the curd seems too thick after adding protein, whisk in a tablespoon of milk or water to loosen it.
  • The raspberry swirl is optional but highly recommended for visual appeal and a tart contrast to the sweet mango. You can substitute any berry puree—strawberry, blueberry, or blackberry. For a seedless swirl, always strain the puree before cooking. The cornstarch slurry ensures the swirl sets without bleeding; if you skip it, the raspberry will sink into the curd and create a messy layer.
  • To achieve perfect, clean slices, refrigerate the bars for at least 2 hours, but overnight is even better. Use a long, sharp chef's knife and wipe it clean with a damp paper towel after each cut. For the smoothest edges, dip the knife in hot water and dry it before slicing—this melts through the curd without dragging.
  • Storage: These bars keep well in an airtight container in the refrigerator for up to 5 days. They also freeze beautifully for up to 3 months. To freeze, wrap each bar individually in plastic wrap, then place in a freezer bag. Thaw overnight in the fridge before serving. The shortbread crust stays crisp, and the curd remains creamy.
  • If you want to boost the protein even further, replace 1/4 cup of the flour in the crust with almond flour or additional protein powder. Note that almond flour will make the crust more delicate, so handle with care. You can also add a tablespoon of collagen peptides to the curd for an extra 5g protein per bar without affecting flavor.

Variations

  • Vegan Adaptation: Replace the butter in the crust with cold coconut oil or vegan butter. For the curd, use 3 tablespoons of cornstarch mixed with 3 tablespoons of water as an egg replacer, or use a commercial egg replacer. Cook the curd over low heat until thickened, about 12-15 minutes. Use a vegan protein powder (pea or soy-based). The texture will be slightly less rich but still delicious.
  • Gluten-Free Option: Substitute the all-purpose flour with a 1:1 gluten-free baking flour blend that contains xanthan gum. Do not use almond flour alone as it won't hold together well. The crust may be more crumbly, so press it firmly and chill before baking. All other ingredients remain the same.
  • Passion Fruit Mango Twist: Replace half of the mango puree with passion fruit pulp (seeds included for texture). The passion fruit adds a tangy, tropical complexity. Adjust sugar to taste, as passion fruit is quite tart. This variation is stunning with the raspberry swirl.
  • Coconut Mango Bars: Add 1/2 cup toasted shredded coconut to the shortbread crust for a tropical crunch. You can also substitute coconut oil for half the butter in the crust. For the curd, use coconut milk instead of butter for a dairy-free version with a subtle coconut flavor.
  • Low-Sugar Version: Use a sugar substitute like erythritol or monk fruit sweetener in both the crust and curd. Note that the curd may not thicken as firmly; add an extra teaspoon of cornstarch to compensate. The raspberry swirl can be made with a sugar-free jam thinned with water.

Nutrition

  • Calories215 kcal
  • Total Fat12g
  • Saturated Fat7g
  • Cholesterol45mg
  • Sodium180mg
  • Total Carbohydrates26g
  • Dietary Fiber1g
  • Sugars17g
  • Protein3g

Common Questions

Can I use frozen mangoes for the puree?
Absolutely! Frozen mangoes are often picked at peak ripeness and work beautifully. Thaw them completely, then puree in a blender until smooth. If the puree is watery, simmer it over low heat for 5-10 minutes to reduce and concentrate the flavor. Let it cool before using in the curd.
Why did my curd turn out lumpy?
Lumpy curd usually means the eggs were cooked too quickly or at too high a heat. Always cook over medium heat and whisk constantly. If lumps appear, immediately remove the pan from heat and whisk vigorously. You can also strain the finished curd through a fine-mesh sieve to remove any lumps. For best results, use an instant-read thermometer and remove from heat at 170°F.
Can I make these bars without protein powder?
Yes, simply omit the protein powder. The bars will have a slightly softer curd and lower protein content (about 3g per bar instead of 8g). You may need to reduce the lemon juice slightly to balance sweetness. The texture will still be delicious, but the curd may be less firm.
How do I know when the bars are fully baked?
The edges should be set and slightly puffed, while the center should jiggle like firm Jell-O when you gently shake the pan. A toothpick inserted near the center should come out with a little curd clinging to it—not wet batter. Overbaking will cause cracks. The bars will continue to set as they cool.
Can I use a different fruit for the swirl?
Definitely! Strawberry, blueberry, blackberry, or even cherry puree work wonderfully. Adjust sweetness to taste. For a tropical twist, try passion fruit or guava puree. The cornstarch slurry ensures the swirl holds its shape, so the same technique applies.
How long do these bars keep at room temperature?
Because the curd contains eggs, it’s safest to refrigerate them. They can be left at room temperature for up to 2 hours during serving, but for longer storage, keep them in the fridge. For picnics, pack them in a cooler with an ice pack.
Can I double the recipe?
Yes, use a 9×13-inch pan and double all ingredients. Baking time for the crust will be similar, but the curd may need an extra 5-10 minutes. Check for doneness as described. You may need to chill longer before slicing.