Preheat your oven to 350°F (175°C). Line a standard cupcake pan with cupcake liners and set aside.
In the bowl of a stand mixer, or in a large bowl with a hand mixer, beat the butter and sugar until light and fluffy, about 2 to 3 minutes.
Add the egg whites one at a time, mixing well after each addition. Mix in the vanilla bean paste and almond extract.
In a separate medium bowl, whisk together the cake flour, baking powder, baking soda, and salt.
With the mixer on low speed, alternate adding the dry ingredients with the sour cream and milk until everything is just combined. Then beat on medium speed for 15 seconds.
Fill the cupcake liners using a large cookie scoop, about 3.5 tablespoons of batter per liner.
Bake for 18 to 22 minutes, or until the centers are set and a toothpick comes out clean.
Let the cupcakes cool in the pan for 5 minutes, then transfer to a wire rack to cool completely.
To make the frosting, beat the butter until smooth and creamy, about 1 minute.
Add the powdered freeze-dried raspberries on low speed. Gradually add the powdered sugar, raspberry puree, milk, vanilla bean paste, and salt.
Increase the speed to high and beat for about 3 minutes, until the frosting is light and fluffy.
Pipe the frosting onto the cooled Raspberry Vanilla Cupcakes. Garnish with fresh mint and a raspberry if desired.