For the muffins:
- 1 cup Darigold FIT milk
- 2 teaspoons white vinegar
- 1/3 cup avocado oil (or other neutral-flavored cooking oil)
- 1/3 cup packed brown sugar
- 1 large egg
- 1 teaspoon pure vanilla extract
- 1 1/2 cups white whole wheat flour (or 50/50 mix whole wheat and all-purpose flour)
- 1 cup old-fashioned oats
- 1 teaspoon baking soda
- 1 teaspoon baking powder
- 1/2 teaspoon kosher salt
- 1 teaspoon ground cinnamon
- 2 1/2 cups grated apple with peel on (from about 2 medium)
For the streusel topping:
- 1/3 cup all-purpose flour
- 3 tablespoons packed brown sugar
- 1/4 teaspoon ground cinnamon
- 1/8 teaspoon kosher salt
- 1/2 stick Darigold unsalted butter at room temperature, cut into 1/2-inch pieces
- Preheat the oven to 350F and lightly grease a muffin pan with oil or cooking spray.
- To make the streusel topping, mix the flour, brown sugar, cinnamon, and salt in a medium bowl. Using your fingers, rub the butter into the mixture until no longer floury and crumbs form. Chill in the freezer for 5-10 minutes or until ready to use.
- To make “buttermilk,” combine the vinegar and milk in a small bowl. Stir well and allow it to sit for a few minutes.
- Meanwhile, combine the oil, brown sugar, egg, and vanilla extract in a blender and pulse a few times to incorporate. Add the flour, oats, baking soda, baking powder, salt, and cinnamon and pulse again until just combined and the mixture begins to stick to the sides. Add the “buttermilk” and apples and mix well with a silicone spatula, making sure to scrape the bottom of the blender. Pulse again 3-5 times to incorporate.
- Scoop the mixture into the greased muffin cups and spoon the streusel mixture on top. Bake for 15-18 minutes or until a toothpick inserted in the center comes out clean and the edges are golden brown. To keep the streusel from getting soggy, store uncovered and enjoy within a few days. Alternatively, leftover muffins can be stored in an airtight container on the counter for 3-5 days, or up to 7 days in the refrigerator.