Using a stand mixer or an electric hand mixer, whisk the butter to a smooth texture. Add the powdered sugar and whisk it again to form a smooth consistency.

Next, sift the flour, baking powder and cocoa powder into the butter mixture. Add the sprinkles and using a paddle attachment, mix it all together to form a crumb like texture.

Pour the milk and give it another mix. Then, form a dough using your hand. If you are having a tough time forming the dough, add a little more milk. Cover the dough in clear wrap and leave it in the refrigerator for 30 minutes.

After 30 minutes, preheat the oven to 350F and layer a cookie sheet with parchment paper.

Take the dough out of the clear wrap and place in on a parchment paper. Roll it into a thin layer. Cut in your desired shape. Place it on the cookie sheet and then, add more sprinkles on top. Bake for 15 minutes.

Let the cookies cool down completely on a cookie wire rack before you store it in a jar.