Preheat the oven to 350 degrees. Line 2 muffin tins with cupcake liners.

In a large bowl cream the butter and sugar. Add in the eggs, one at a time, stirring until combined. Stir in the vanilla.

In a small bowl combine the flour, baking powder, and sea salt.

Add half the flour mixture to the butter mixture and mix well. Stir in the SunnyD. Add the remaining flour and mix well to combine.

Divide the batter between the muffin cups, filling 2/3 of the way full.

Bake for 20-25 minutes or until a toothpick inserted into the center comes out clean.

Cool completely on a wire rack.

In a large bowl beat the butter with a mixer until smooth. Add in the powdered sugar ½ cup at a time until desired consistency is reached.

Add in the vanilla and SunnyD and mix until smooth.

Frost the cupcakes with the vanilla SunnyD frosting.