1Preheat oven to 350F. Line your sheet pan with parchment paper.
2Dice the (cold) butter into small cubes. Using a hand or stand mixer, cream the butter and sugar together.
3Combine all dry ingredients (flour, powdered milk, baking powder, and Nesquick) in a separate bowl.
4Add the eggs and vanilla to the creamed butter & sugar mixture. Mix just until combined.
5Add all dry ingredients into the mix. Mix slowly, at first, to begin incorporating them into the dough. Once everything is coming together, mix slightly faster, just until combined. (This part can also be done by hand.)
6Add white chocolate chips. Mix just until they are evenly distributed.
7Dough may seem a bit crumbly... don't worry! That's ok!
8Pour some sprinkles out into a small dish. You'll need these in a minute...
Using a teaspoon as your scoop, take a bit of dough from the bowl. Roll it into a ball in your palms, bringing the dough into a nice round. Press it slightly between your hands to flatten it out just a bit.
Dip the round - one flat side down - into the sprinkles. Press firmly (but not so firmly as to squish the dough) so that the sprinkles will stick to the dough.
Place the cookie dough - sprinkle side up - on the cookie sheet. Continue like this until your tray is full, leaving about 2" between each ball.
9Bake for about 12-15 minutes, turning halfway through until cookies are just beginning to become golden at the edges. Remove from the oven and allow to cool. Once cookies have begun to firm up, carefully transfer them to a cooling rack.
10Store in an air-tight container for up to one week.