Brown the butter. In a saucepan, melt butter over medium-low heat. Increase heat to medium and cook, stirring constantly. Butter will sizzle and pop. Once popping slows or stops and you notice the butter is beginning to turn golden brown (there will be brown flecks on the bottom of your pan) immediately remove from heat. Pour into a large heatproof mixing bowl and allow to cool completely until no longer warm to the touch before proceeding.

Preheat oven to 375F (190C) and line a 12-count muffin tin with paper liners.

Once butter has cooled, add sugar, egg, and vanilla extract and whisk very well until ingredients are well combined.

Stir in buttermilk.

In a separate bowl, whisk together flour, baking powder, baking soda, and salt.

Add the flour mixture to the wet ingredients and use a spatula to gently fold together until about halfway combined.

Add peaches and stir until ingredients are completely combined. Don’t over-mix or muffins will be dense.

Evenly divide batter into prepared muffin tin and sprinkle with coarse sugar.

Transfer to center rack of 375F (190C) oven and bake for 20 minutes or until a toothpick inserted in the center comes out clean or with moist crumbs.

Allow muffins to cool in baking pan for 5 minutes before carefully removing to a cooling rack to cool completely. If you'd like to add a glaze, drizzle with my easy vanilla glaze once muffins have cooled.