1-Preheat oven: Preheat oven to 425°F and prepare muffin pans with spray or liners.

2-For the crumb topping: combine 1/3 cup packed light or dark brown sugar, 1 tablespoon granulated sugar, and 1 teaspoon ground cinnamon. Stir in 1/4 cup melted unsalted butter, then fold in 2/3 cup all-purpose flour with a fork to keep it crumbly. Set aside.

3-In a large bowl, whisk together 1 3/4 cups all-purpose flour, 1 teaspoon baking soda, 1 teaspoon baking powder, 1 teaspoon ground cinnamon, and 1/2 teaspoon salt.

4-Using a mixer, beat 1/2 cup softened unsalted butter with 1/2 cup packed light or dark brown sugar and 1/4 cup granulated sugar until creamy. Add 2 large eggs at room temperature, 1/2 cup yogurt or sour cream at room temperature, and 2 teaspoons pure vanilla extract, beating until combined.

5-Gradually add the dry ingredients and 1/4 cup milk at room temperature to the wet mixture, mixing on low speed until just combined. Fold in 1 1/2 cups chopped apples.

6-Fill muffin tins to the top with batter, spoon the crumb topping over the muffins, and gently press it to adhere.

7-Bake at 425°F for 5 minutes, then reduce the temperature to 350°F and bake for an additional 15-18 minutes until a toothpick comes out clean. Cool muffins in the pan for 5 minutes, then transfer to a rack.

8-If using vanilla icing, mix 1 cup confectioners’ sugar, 3 tablespoons heavy cream or milk, and 1/2 teaspoon pure vanilla extract, then drizzle over the muffins once they are warm or cooled.