Preheat oven to 350 degrees f
Mix dry muffin ingredients (flour, sugar, baking powder, and salt) in one large bowl
Grab a separate bowl and mix the wet ingredients (butter, sour cream, egg, orange juice, and orange zest)
Pour wet ingredients over dry ingredients and stir until moist
Put batter into a greased/sprayed muffin pan (we like to use muffin liners)
Bake about 15 - 18 minutes at 350 degrees f until done (passes the toothpick test!)
Cool on a wire rack
Once cooled, pour glaze on the muffin tops (to make the glaze, simply mix the ingredients together until combined)
Enjoy!