Preheat your oven to 350°F (175°C) and prepare three 6x2 inch cake pans by greasing and lining with parchment paper.

In a medium bowl, whisk together the all-purpose flour, baking powder, baking soda, and salt until combined.

In your stand mixer, beat the softened unsalted butter until fluffy, then gradually add granulated sugar until light and creamy.

Add egg whites one at a time, then blend in the vanilla bean paste until well combined.

With the mixer on low speed, add sour cream, then milk, mixing until just combined.

Gradually add the flour mixture to the wet ingredients, alternating with the milk, mixing just until combined.

Evenly distribute the batter among the three prepared cake pans and smooth the tops.

Bake for 18-20 minutes or until a toothpick comes out clean.

Cool in the pans for 10 minutes, then invert onto a wire rack to cool completely.

Prepare the frosting by pureeing fresh strawberries until smooth. Beat together cream cheese and softened butter until fluffy.

Gradually add pureed strawberries, mixing until well combined.

Slowly incorporate powdered sugar until you reach your desired frosting consistency.

Once cakes are cool, layer the frosting between the cakes and on top, then serve and enjoy!