Step 1: Preheat the Oven - Preheat your oven to 375°F (190°C). This ensures that your muffins bake evenly and rise perfectly.
Step 2: Prepare the Muffin Tin - Grease your muffin tin with cooking spray or line it with paper liners.
Step 3: Mix the Dry Ingredients - In a large mixing bowl, whisk together the all-purpose flour, cornmeal, baking powder, ground cinnamon, pumpkin spice, and kosher salt.
Step 4: Combine Wet Ingredients - In another bowl, beat together the softened unsalted butter and sweetened condensed milk until smooth. Add in the eggs, buttermilk, pumpkin puree, and vanilla extract. Mix until well combined.
Step 5: Combine Dry and Wet Ingredients - Gradually add the dry ingredients to the wet mixture, stirring gently with a rubber spatula.
Step 6: Fill the Muffin Tin - Spoon the muffin batter into each cup, filling each about three-quarters full.
Step 7: Bake - Place the muffin tin in the preheated oven and bake for 18-22 minutes, or until a toothpick comes out clean.
Step 8: Cool and Enjoy - Remove the muffins from the oven and let them cool in the tin for about 5 minutes before transferring to a wire rack.