01 -
Stir the sugar and cinnamon together in a tiny bowl. Put it aside.
02 -
Blend butter, sugar, and salt together well. Stir in the egg, milk, yeast, and flour until the mix is nice and smooth. Fold in most of the sprinkles, and let it rest in a cozy spot for about 90 minutes.
03 -
Flatten the dough into a 9x12-inch sheet. Spread some butter on it, scatter the cinnamon-sugar mix and leftover sprinkles on top. Roll it up and slice it into 8 equal pieces.
04 -
Arrange the pieces in a greased cast iron pan, cover them up, and pop them into the fridge. When you're ready the next day, let them sit in a cozy spot for another hour and a half.
05 -
Bake at 325°F for 32-34 minutes until golden brown. Cool for 15 minutes, then drizzle with a glaze made by whisking powdered sugar, milk, and vanilla. Sprinkle extra sprinkles on top.