Preheat the oven to 375℉. Line a 12 tin muffin liner with 12 liners and set aside. You can use regular liners or tulip liners for a taller bake like I did. Just note that tulip liners do require a longer bake because there is more batter in the muffins. Chop the apples (skin on or off, up to you) into small pieces and set aside.
2 cups apples
In a small bowl, make the streusel. Combine flour, white sugar, brown sugar, cinnamon, and cold cut up butter. Using your hands, mix it together until combined into a crumbly, streusel mixture. Set aside while you make the muffin batter.
1/2 cup flour, 1/4 cup light brown sugar, 1/4 cup white sugar, 1/4 tsp cinnamon, 3 tbsp butter
In a medium-sized bowl, add in flour, baking soda, baking powder, cinnamon, nutmeg, allspice, and salt. Mix together and set aside.
2 cups all purpose flour, 2 tsps baking powder, 1 tsp baking soda, 1/2 teaspoon salt, 1 1/2 tsps cinnamon, 1/8 tsp nutmeg, pinch of allspice
In a large bowl, add brown sugar, oil, eggs, vanilla, and sour cream. Whisk until well combined.
1 cup light brown sugar, 3/4 cups sour cream, 1/2 cup oil, 2 large eggs, 1 tbsp vanilla
Pour the dry ingredients into the wet and using a spatula, gently fold to create a soft muffin batter.
Mix in the apples until just combined.
2 cups apples
Evenly divide the batter between 12 liners, they should be almost or all the way full. Using a cookie scooper helps big time to minimize the mess. Sprinkle cinnamon white sugar on top.
Bake the muffins at 375°F for 18-24 minutes The muffins are ready when they bounce back at touch or a toothpick inserted comes out clean.