Start with the crumb topping. In a small bowl, whisk together the flour, brown sugar, granulated sugar, and cinnamon.

Add the softened butter and work it into the dry ingredients with a fork until coarse crumbs form. No butter pieces should be larger than a pea. Set aside.

Preheat the oven to 425°F (220°C). Lightly grease a standard 12-cup muffin pan or line it with paper liners.

In a medium bowl, whisk together the flour, baking powder, baking soda, cinnamon, and salt.

In a separate large mixing bowl, beat the softened butter, brown sugar, and granulated sugar with an electric mixer on medium speed until smooth and creamy.

Add the eggs, sour cream, milk, and alcohol-free vanilla. Mix until thoroughly combined.

Add the dry ingredients to the wet mixture.

Stir gently just until no obvious streaks of dry flour remain. Avoid overmixing.

Fold the chopped apples gently into the batter until evenly distributed.

Divide the batter among the 12 prepared muffin cups, filling each close to the top.

Generously distribute the crumb topping over the muffin batter, pressing some of the larger crumbs very lightly into the surface.

Bake the Moist Apple Cinnamon Crumb Muffins at 425°F for 5 minutes.

Without opening the oven door, reduce the temperature to 350°F (175°C).

Continue baking for 15–18 minutes, or until the muffins are golden and a toothpick inserted into the center comes out clean or with a few moist crumbs.

Remove the muffin pan from the oven and allow the muffins to cool in the pan for about 5 minutes.

Carefully transfer the muffins to a wire rack and allow them to cool further before serving.