- First, make the crumb topping: In a medium bowl, combine both sugars, the cinnamon, and melted butter. Using a rubber spatula, stir in the flour. The crumb topping will be thick and crumbly. Set aside.
- Preheat oven to 425°F (218°C). Spray a 12-count muffin pan with nonstick spray. Set aside.
- Make the muffins: In a medium bowl using a handheld or stand mixer fitted with a paddle attachment, beat the butter on high speed until smooth and creamy, about 1 minute. Add the brown sugar and granulated sugar and beat on high until creamed, about 2 full minutes. Scrape down the sides and bottom of the bowl as needed. Add the eggs, yogurt, and vanilla extract. Beat on medium speed for 1 minute, then turn up to high speed until the mixture is combined and uniform in texture. Scrape down the sides and bottom of the bowl as needed.
- In a large bowl, toss together the flour, baking soda, baking powder, cinnamon, all-spice, and salt. Pour the wet ingredients into the dry ingredients and slowly mix with a whisk. Add the milk, gently whisking until combined and little lumps remain. Fold in the peaches with a wooden spoon or rubber spatula.
- Spoon the muffin batter evenly between all 12 muffin tins. There may be enough to make a 13th muffin in a 2nd batch, depending if there were a few extra peach chunks thrown in. Fill the muffin tins until they are full all the way up to the top. Press a handful of the crumb topping into the top of each; crumble it with your hands to make some big chunks.
- Bake for 5 minutes at 425°F (218°C), then keeping the muffins in the oven, lower the oven temperature to 350°F (177°C) and bake for 15-19 more minutes or until a toothpick inserted in the center comes out clean.
- Make the glaze: whisk all of the ingredients together and drizzle over warm muffins.
