Preheat oven to 350 degrees. In a medium bowl, whisk together flour, baking powder, salt, and baking soda. In a large bowl using an electric mixer on medium-high, beat butter and sugar until light and fluffy, 2 to 4 minutes. Add egg and vanilla; beat well to combine. Switch the mixer to low, add half the flour mixture, followed by sour cream, then remaining flour mixture; mixing just until smooth. Carefully fold in sprinkles.