Preheat and prep: Set your oven to 400°F (200°C). Line a 12-cup muffin tin with paper liners or grease the cups lightly.

Mix dry ingredients: In a large bowl, whisk together flour, baking powder, baking soda, salt, cinnamon, and nutmeg. This helps distribute the leavening and spices evenly.

Whisk wet ingredients: In a separate bowl, whisk granulated sugar, brown sugar, oil, yogurt, eggs, and vanilla until smooth and slightly thick. The sugars should be fully moistened.

Prep the apples: Peel, core, and dice the apples into small cubes (about 1/4-inch). Toss with a splash of lemon juice if you like to keep them bright.

Combine: Pour the wet mixture into the dry bowl. Stir gently with a spatula until the flour is mostly combined. It’s okay if a few streaks remain.

Fold in apples (and mix-ins): Add the diced apples and any optional nuts or raisins. Fold just until distributed. Do not overmix or the muffins can turn tough.

Fill the pan: Divide the batter evenly among 12 cups, filling them nearly to the top for a tall muffin. If using the topping, stir cinnamon and sugar together and sprinkle over each muffin.

Bake hot, then reduce: Place the tin in the oven and bake at 400°F for 5 minutes. Without opening the door, reduce heat to 350°F (175°C) and bake another 12–15 minutes, until a toothpick comes out clean or with a few moist crumbs.

Cool: Let muffins rest in the pan for 5 minutes, then move to a wire rack to cool. They’ll firm up as they sit, so resist cutting into them immediately.

Serve: Enjoy warm or at room temperature. A pat of butter or a drizzle of honey is lovely but optional.