Preheat your oven to 350°F (175°C).
Line a muffin tin with parchment liners.
In a mixing bowl, combine the sifted coconut flour, cupcake batter protein powder, and salt. Whisk well.
In another bowl, beat the eggs until frothy. Add honey, 1 tablespoon Greek yogurt, melted coconut oil, vanilla extract, and optional butter extract. Mix well.
Pour the wet ingredients into the dry ingredients and stir gently until just combined.
Fill each muffin cup about three-quarters full with the batter.
Bake for 15-20 minutes or until a toothpick comes out clean.
Cool the cupcakes in the tin for 5 minutes, then transfer to a cooling rack.
In a clean bowl, combine the remaining 1/3 cup Greek yogurt with 1/4 cup cupcake batter protein powder and stevia to taste. Mix until smooth and fold in rainbow sprinkles.
Spread the Funfetti icing on top of completely cooled cupcakes and enjoy!
