In a large mixing bowl, beat the softened butter and granulated sugar until light and fluffy. Add the egg yolk and mix until fully incorporated.
Add dry ingredients
Add the flour and baking powder directly to the bowl. Mix just until a soft dough forms. Do not overmix.
Shape the cookies
Scoop tablespoon-sized portions of dough and roll into balls. Place on a parchment-lined tray. Press several candy-coated chocolates gently into the top of each dough ball.