Preheat that oven to 350°F. Go ahead and line a baking sheet with parchment paper while you’re at it.
Unroll your pie crusts and cut each one into 4 even rectangles.
Mix up the filling. In a medium bowl, whisk together the pudding mix, cold milk, and yellow cake mix until smooth. Stir in a tablespoon of sprinkles for good measure.
Spoon the filling onto half of your pie crust rectangles, leaving a little room around the edges.
Top them off with the other rectangles. Use a fork to crimp the edges.
Cut 3 little slits in the top of each pie so they can breathe while baking.
Make a quick egg wash by beating the egg with a tablespoon of water. Brush it over each pie, then sprinkle a few more sprinkles on top.
Bake for 15–20 minutes until they’re golden brown and smell like heaven.
Serve warm and watch folks fall in love.
Notes
Store leftovers in an airtight container for up to 2 days (if they last that long).
Switch up the sprinkle colors for different holidays: red and green for Christmas, pastels for Easter, or go full-on glitter for New Year’s!
Feeling fancy? Try puff pastry instead of pie crust for a flakier bite.