Basic Instructions

• Preheat oven to 425°F (218°C). Spray a 12-count muffin pan with nonstick spray or line with cupcake liners. You may need a 2nd pan as this recipe makes up to 14 muffins, though you can always bake in batches using 1 pan. Set aside.
• Make the crumb topping: Mix the brown sugar, granulated sugar, and cinnamon together in a medium bowl. Stir in the melted butter, and then gently mix in the flour using a fork. Keep the mixture as large crumbles and do not over-mix.
• Make the muffins: Whisk the flour, baking soda, baking powder, cinnamon, and salt together in a large bowl. Set aside.
• Using a handheld or stand mixer fitted with a paddle attachment, beat the butter and both sugars together on high speed until smooth and creamy, about 3 minutes. 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.
• With the mixer running on low speed, add the dry ingredients and milk into the wet ingredients and beat until no flour pockets remain. Fold in the apples.
• Spoon the batter evenly into each cup or liner, filling each all the way to the top. Spoon crumb topping on each, gently pressing it down so it sticks.
• Bake for 5 minutes at 425°F, then reduce the oven temperature to 350°F (177°C). Bake for an additional 15–18 minutes or until a toothpick inserted in the center comes out clean.
• Allow the muffins to cool for 5 minutes in the muffin pan, then transfer to a wire rack to continue cooling.
• Make the icing: Whisk all of the icing ingredients together and drizzle over warm or cooled muffins.
• Iced or plain muffins stay fresh covered at room temperature for a few days or in the refrigerator for up to 1 week.