Preheat oven to 350F and line baking sheet with parchment paper.
Mix together all dry ingredients and set aside.
In another bowl, mix together wet ingredients.
Mix the wet and dry ingredients together and stir until combined. Store dough in fridge for 30 minutes to chill.
Add in the sprinkles, roll into balls using wet hands if dough is sticky, and flatten slightly onto baking sheet. Bake for 13-15 minutes or until fully cooked through.
While they are cooling, mix together powdered sugar, water, and vanilla. Once cookies have cooled completely, frost them and add more sprinkles.
Store in fridge.