Plug in your Mini Bundt maker to preheat for 10 minutes.
In a small mixing bowl, combine flour, cocoapowder, baking powder, baking soda, and salt.
In a measuring cup, whisk buttermilk, egg, vinegar, vanilla, and red food color together.
In a medium mixing bowl, beat butter and sugar with handheld mixer on medium util fluffy and light. Add 1/3 of dry ingredients, blend, then ½ wet ingredients. Repeat until combined.
Brush Bundt maker and removal tool, if using, with butter or spray with baking spray. Fill the mini Bundt maker ¾ full (1/3cup batter)
Bake for 12 minutes, until a toothpick comes out clean when inserted into the cake.
Lift out cake using the removal tool or knife if not using the removal tool. Cool cake completely before glazing.
Sift powdered sugar into mixing bowl and combine with cream cheese. Add the milk and stir vigorously until the glaze is smooth and creamy
After cakes are cooled, use spatula to pour glaze over cakes. Sprinkle on your sprinkles and serve.