• Prep: Preheat oven to 350°F/175°C. Line a muffin tin with 12 liners or lightly grease.

Crumble Topping

• Make crumble topping: In a small bowl, stir together flour, brown sugar, and cinnamon. Cut in vegan butter with a fork until the mixture resembles coarse crumbs. Set aside.
  ⅓ cup all-purpose flour, ¼ cup brown sugar, ½ teaspoon ground cinnamon, 2 tablespoons vegan butter

Muffins

• Mix wet ingredients: In a large mixing bowl, whisk together brown sugar, oil, milk, apple cider vinegar, and vanilla.
  ½ cup plant-based milk, ½ cup brown sugar, ⅓ cup vegetable oil, 1 teaspoon apple cider vinegar, 1 teaspoon vanilla extract
  
• Mix dry ingredients: In a separate bowl, stir together flour, baking powder, baking soda, salt, cinnamon, and nutmeg.
  2 cups all-purpose flour, 1 teaspoon baking powder, ½ teaspoon baking soda, 1 teaspoon ground cinnamon, ½ teaspoon ground nutmeg, ½ teaspoon salt
  
• Combine: Add dry mixture into wet, stirring gently until just combined (do not overmix). Fold in diced apples.
  1 cup apple
• Fill muffin tin: Divide batter evenly among muffin cups (about ¾ full). Sprinkle each muffin generously with crumble topping.
  
• Bake: Bake 20–24 minutes, until a toothpick inserted into the center comes out clean.
• Cool & serve: Let muffins cool in the pan for 5 minutes before transferring to a wire rack. Enjoy warm or at room temperature.
• Store muffins in an airtight container at room temperature for up to 3 days, in the fridge for up to 7 days, or in the freezer for up to 2 months.