INGREDIENTS
For the muffins:
1 and ½ cups all-purpose flour
½ cup sugar
¼ cup packed brown sugar
1 and ½ teaspoons baking powder
¼ teaspoon salt
½ teaspoon cinnamon
Pinch nutmeg
7 tablespoons (not quite 1 stick) unsalted butter
1 large egg
1 large egg yolk
⅓ cup milk
2 teaspoons vanilla
1 and ¼ cups diced peaches (1/4-inch dice)

For the topping:
3 tablespoons unsalted butter, cold
½ cup all-purpose flour
¼ cup packed brown sugar
Pinch salt
Pinch nutmeg
¼ teaspoon cinnamon

DIRECTIONS
Preheat oven to 350 degrees F. Butter and flour an 8-loaf mini loaf pan (or a 12-cup muffin pan).

Make the muffins:
In a medium bowl, combine flour, sugar, brown sugar, baking powder, salt, cinnamon and nutmeg. In a small saucepan, melt butter over medium heat. Continue cooking until butter browns, swirling pan to encourage even browning. Remove from heat and cool slightly.
In a medium bowl, mix egg, egg yolk, milk and vanilla and whisk to combine. While whisking, slowly pour in the warm butter (and any bits that may cling to the saucepan). Whisk until well blended.
Add the milk-butter mixture to the flour mixture and fold together with a spatula until no dry streaks remain. Fold in diced peaches. Divide the batter between the 8 loaf cups.

Make the topping:
Combine all topping ingredients in a small bowl and blend with your fingers until the butter pieces are nearly incorporated and resemble small peas. Sprinkle topping evenly over each loaf.
Bake for 20-25 minutes, until the tops are golden brown and a tester inserted in the centre comes out clean. Cool in the pan for 20 minutes before removing. Muffins will keep covered at room temperature for 2-3 days.

(Note: If you're making muffins, the cook time will be more like 15-18 minutes, so start checking them earlier!)