1-Make Streusel: Combine the streusel ingredients ⅓ cup white flour, 1 tablespoon quick cooking oats, ½ teaspoon cinnamon, and 2 tablespoons brown sugar and cut in 2 tablespoons cold stick butter until crumbs form. Chill the streusel to keep it crisp.

2-Preheat & Prep: Preheat your oven to 425°F and line a muffin tin with paper liners for easy removal later.

3-Combine Dry: In a large bowl, mix all the dry ingredients: ½ cup white flour, ¾ cup whole wheat flour, 2 tablespoons cornstarch, 1 teaspoon baking powder, ¼ teaspoon salt, 1 teaspoon cinnamon, and ½ teaspoon apple pie spice.

4-Combine Wet: In a separate bowl, whisk together the wet ingredients: 1 large egg, ¾ cup plain Greek yogurt, ¼ cup oil, 2 tablespoons maple syrup, 1 teaspoon vanilla extract, and ⅓ cup light brown sugar until smooth.

5-Mix Batter: Gently fold the wet ingredients into the dry ingredients just until combined, being careful not to overmix. Then, fold in 1 cup peeled and chopped apple to add that fresh burst of flavor.

6-Fill & Top: Divide the batter evenly among the muffin cups, filling them about three-quarters full, and sprinkle the chilled streusel topping on each one.

7-Bake: Reduce the oven temperature to 400°F and bake for 5 minutes, then lower it to 350°F and continue baking for 15 to 18 minutes, or until a toothpick inserted comes out clean.

8-Cool: Let the muffins cool on a wire rack for 5 minutes before removing them from the pan, then finish cooling on the rack for the best texture.