01 -
Combine rolled oats and whole milk in a medium bowl and let soak for at least 15 minutes to soften oats and ensure moist texture.
02 -
In a large bowl, whisk together all-purpose flour, baking powder, baking soda, salt, ground cinnamon, ground nutmeg, and brown sugar until evenly incorporated and lump-free.
03 -
Beat the egg lightly in a separate bowl, then whisk in vegetable oil and vanilla extract until fully blended.
04 -
Add the soaked oats mixture and wet ingredients to the dry ingredients. Fold gently until just combined to avoid dense muffins.
05 -
Fold in the finely chopped Honeycrisp apples, distributing them evenly throughout the batter.
06 -
Divide batter evenly among a greased or lined 12-cup muffin tin. Bake in a preheated oven at 375°F (190°C) for 18 to 22 minutes, or until a toothpick inserted in the center comes out clean.
07 -
Allow muffins to cool in the pan for 5 minutes before transferring them to a wire rack to cool completely. Serve warm or at room temperature.