• Preheat the oven to 375°F. Line the muffin liners with 12 liners and set aside. You can use regular liners or tulip liners. This recipe makes 8 tulip liner muffins, and 12 regular-sized muffins.

For the streusel

• 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 in the fridge while you make the muffin batter.
  1/2 cup all-purpose flour, 1/4 cup light brown sugar, 1/4 cup white sugar, 1/4 tsp cinnamon, 3 tbsp butter

For the muffins

• In a medium-sized bowl, add in flour, oats, baking soda, baking powder, cinnamon, nutmeg, allspice, and salt. Mix together and set aside.
  1 1/2 cups all-purpose flour, 1 cup rolled oats, 1 tsp baking soda, 1 1/2 tsps baking powder, 1 tsp cinamon, 1/8 tsp nutmeg, 1/4 tsp salt
• In a large bowl, add brown sugar, oil, sour cream, eggs, applesauce, and vanilla. Whisk together until well combined.
  3/4 cups light brown sugar, 1 1/4 cups unsweetened applesauce, 1/2 cup sour cream, 2 eggs, 1/3 cup oil, 1 tsp vanilla
• Pour the dry ingredients into the wet and using a spatula, gently fold to create a soft muffin batter.
• 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 streusel on top.
• Bake the muffins at 375°F for 15-20 minutes for regular liners. If you're baking the muffins in tulip liners, they will take anywhere from 20-25 minutes. The muffins are ready when a toothpick inserted comes out clean. Every oven differs, so keep an eye out after the 15 minute mark.
• These muffins stay fresh covered at room temperature for a few days, or in the refrigerator in an airtight container for up to 1 week!