A delightful twist on classic apple muffins, featuring a nutty crumble topping and a moist, flavorful interior.
Preheat your oven to 350°F (175°C) and grease a muffin tin.
Ensure the oven is fully preheated before baking for even cooking.
In a mixing bowl, cream together the butter and brown sugar until light and fluffy.
Use room temperature butter for easier mixing.
Add the egg and mix well. Stir in the sour cream until combined.
Mix until just combined to avoid overmixing.
In another bowl, whisk together the flour, cinnamon, and nutmeg. Gradually add this to the wet mixture.
Add the dry ingredients in batches to prevent lumps.
Fold in the diced apples gently.
Ensure the apples are evenly distributed in the batter.
In a small bowl, mix the crumble topping ingredients: walnuts, brown sugar, flour, and cold butter. Use your fingers to create a crumbly texture.
Keep the butter cold for a better crumble texture.
Spoon the batter into the muffin tin, filling each cup about 3/4 full. Sprinkle the crumble topping over each muffin.
Press the crumble topping lightly to help it adhere to the batter.
Bake in the preheated oven for 25-27 minutes, or until a toothpick inserted into the center comes out clean.
Rotate the muffin tin halfway through baking for even browning.
Let the muffins cool in the tin for 5 minutes before transferring them to a wire rack to cool completely.
Cooling on a rack prevents the muffins from becoming soggy.