01 - Preheat oven to 350°F. Line a 12-cup muffin tin with paper liners or grease thoroughly.
02 - In a large bowl, whisk together flour, 1 cup crushed cornflakes, granulated sugar, baking powder, baking soda, salt, cinnamon, and nutmeg until evenly combined.
03 - In a separate bowl, whisk pumpkin puree, eggs, melted butter, milk, and vanilla extract until smooth.
04 - Pour wet mixture into the bowl with dry ingredients. Stir gently until just incorporated. Avoid excessive mixing.
05 - Divide the batter among the prepared muffin cups, ensuring even distribution.
06 - In a small bowl, mix 1 cup crushed cornflakes with melted butter and brown sugar. Sprinkle topping evenly over each muffin portion.
07 - Place the tin in the oven and bake for 20 to 22 minutes, or until a toothpick inserted in the center withdraws clean.
08 - Allow muffins to cool in the tin for 5 minutes, then transfer to a wire rack to finish cooling.