Preheat Oven: Set to 375°F (190°C).
Mix Muffin Batter: Combine dry ingredients. In a separate bowl, mix milk, oil, and egg, then fold in apples. Combine with dry ingredients.
Make Streusel: Mix flour, brown sugar, cinnamon, and butter until crumbly.
Assemble & Bake: Fill muffin liners ¾ full, top with streusel, and bake for 18–20 minutes.
Serve: Let cool slightly before enjoying!
Optional: Drizzle with vanilla glaze for a sweet finish.
