These strawberry cupcakes are basically strawberry shortcake with better structure; a light vanilla cake folded with whipped egg whites so it bakes up soft and airy, packed with fresh straberries, then filled with a cool mascarpone cream. The frosting is a white chocolate Swiss meringue buttercream - silky, not too sweet, and the kind of finish that makes them look bakery level without tasting like straight sugar.

What is mascarpone?

Mascarpone is a rich, ultra creamy Italian fresh cheese that’s closer to thick cream than something sharp or tangy like cream cheese. It’s traditionally made by curdling cream with an acid (like lemon juice or tartaric acid), then draining it until it turns into this smooth, buttery, spreadable texture. Flavor wise it’s mild, slightly sweet, and super neutral which is why it’s the backbone of desserts like tiramisu and why it whips beautifully into fillings; it adds body and silkiness without overpowering whatever you mix in (strawberries, vanilla, espresso, citrus, you name it).

How to make strawberry mascarpone cupcakes?

Preheat oven to 350f and line cupcake tins. In a small bowl whisk together flour, baking powder, and 1/2 tsp of salt. In a separate bowl whisk 4 egg whites until stiff peaks form, set aside. In a large bowl cream together 3/4 cup of butter and 1 cup + 2 tbsp of sugar until light and fluffy. Then add 1 tsp vanilla extract and sour cream. Gradually add the flour mixture and mix until smooth. Gently fold in half of the whipped egg whites until mostly combined, then fold in rest of the egg whites and chopped strawberries. Fill each cupcake liner 3/4 full and bake for 22-25 minutes. Cool on a wire rack. Make mascarpone filling by whipping heavy cream with powdered sugar until soft peaks form. In a separate small bowl whisk together mascarpone and 1 tsp vanilla extract. Gently whisk the two together until just combined. Cover and refrigerate. Make Swiss meringue buttercream by bringing 1” of water to boil in a small pot. In a large heat proof bowl whisk together 5 egg whites, 1 1/2 cups of sugar, and a pinch of salt. Place the bowl over the boiling water and lower the heat to medium. Whisk constantly until the temperature reaches 165f. Remove from heat and whisk on high speed until the meringue is at room temperature. Switch to paddle attachment in your kitchen aid to beat in 2 cups of butter 1 tbsp at a time. Keep it on medium high speed until light and fluffy, about 15-20 minutes. Meanwhile melt and cool the white chocolate. Once the buttercream is smooth slowly drizzle in the white chocolate while mixing on medium speed. Add food coloring if desired. Cut a thumb sized hole in the middle of each cupcake and fill it with the mascarpone filling. Then frost the cupcakes with the white chocolate Swiss buttercream.