Preheat oven to 350 degrees. Line two standard cupcake pans (or three minis) with liners, set aside.
In the bowl of a stand mixer, beat butter and sugars until light and fluffy, about 3 minutes. Add vanilla bean paste and almond extract. With mixing speed on low, add egg, then egg yolk, mixing until just combined.
In a medium size mixing bowl whisk together flour, cake flour, baking powder, baking soda, and salt. In a glass measuring cup mix together sour cream and milk. With mixing speed on low, alternate dry and wet ingredients, mix until batter is smooth and homogeneous (being careful not to over mix).
Remove bowl from stand and gently fold in sprinkles. Scoop batter into the cupcake liners, filling each ⅔ of the way full. Place in the oven and bake for 18-22 minutes (8-12 for minis) or until the cupcakes spring back when touched and are slightly golden brown on top.
Remove from oven and allow to cool in pans for 5 minutes before removing and transferring to a wire rack to cool completely (about 25 minutes).
While cupcakes are cooling, in the bowl of a stand mixer fitted with the whisk attachment, combine butter, salt, vanilla and almond. Beat until fluffy (2-3 minutes). With mixing speed on low, add heavy cream, then gradually add ½ c. powdered sugar at a time until the mixture becomes soft but firm enough to hold it’s shape. Beat frosting for an additional 3 minutes until light and fluffy. Pipe on cooled cupcakes as desired, decorate with sprinkles.