2 cups Granny Smith apples, peeled and finely diced
For the Crumble:
1/2 cup all-purpose flour
1/2 cup brown sugar, packed
1 teaspoon ground cinnamon
1/4 cup cold unsalted butter, cubed
Instructions
Preheat your oven to 375°F (190°C). Line a 12-cup muffin tin with paper liners or grease it thoroughly with non-stick cooking spray to ensure the muffins release easily after baking.
In a small bowl, combine 1/2 cup flour, 1/2 cup brown sugar, and 1 teaspoon of cinnamon. Use a fork or a pastry cutter to cut in the cold, cubed butter until the mixture resembles coarse crumbs. Set this aside in the refrigerator to keep the butter cold.
In a large mixing bowl, whisk together the 2 cups of flour, granulated sugar, baking powder, 1 1/2 teaspoons of cinnamon, and salt. Ensure there are no large lumps of flour or sugar remaining.
In a separate medium bowl, whisk the melted butter, milk, eggs, and vanilla extract until well combined. Make sure your eggs are at room temperature so they don’t cause the melted butter to seize up.
Pour the wet ingredients into the dry ingredients. Use a spatula to gently fold the mixture together until just combined. Be careful not to overmix, as this can lead to tough muffins; a few small streaks of flour are okay.
Gently fold the finely diced apples into the batter. The batter will be thick, which is exactly what you want for a bakery-style structure that supports the weight of the fruit and crumble.
Divide the batter evenly among the 12 muffin cups, filling each almost to the top. Generously sprinkle the prepared crumble topping over each muffin, pressing it down slightly so it sticks.
Bake for 20 to 25 minutes, or until a toothpick inserted into the center of a muffin comes out clean or with just a few moist crumbs. Let the muffins cool in the tin for 5 minutes before transferring them to a wire rack.