Preheat the oven to 350 F, and position a rack in the center of the oven. Line your muffin pans with 19 paper cupcake liners.
In the bowl of your stand mixer fitted with the paddle attachment, beat the softened butter with the sugar for about 3-5 minutes on medium speed, scraping the bowl frequently, until light and fluffy.
Beat in the egg whites, one at a time, until well combined.
In a separate bowl, sift together the flour, baking powder and salt. In another bowl or liquid measuring cup, whisk together the buttermilk, sour cream, vanilla and almond extracts.
With the mixer on low, add the flour mixture in three additions, alternating with the buttermilk mixture, starting and ending with the flour. Once you've added everything, mix well for about 15-30 seconds until the batter is well combined.
Briefly fold in the sprinkles, just until evenly dispersed throughout the batter.
Use a scant 1/4 measuring cup to fill the muffin cups, filling them no more than 2/3 full. If you like, sprinkle the top of the batter with a few more sprinkles.
Bake the cupcakes for about 15-16 minutes, just until the tops spring back when gently touched. Cool in the pan for several minutes, then gently transfer the cupcakes to a cooling rack to cool completely before frosting.