01 - Preheat oven to 350°F (175°C). Line each cavity of a 12-cup muffin tin with paper liners.
02 - In a medium mixing bowl, thoroughly whisk together flour, baking powder, baking soda, salt, cinnamon, ginger, nutmeg, and cloves.
03 - In a large bowl, combine vegetable oil, granulated sugar, brown sugar, and eggs. Mix until smooth. Add pumpkin purée, milk, and vanilla extract; stir until fully incorporated.
04 - Gradually fold the dry ingredients into the wet mixture. Mix only until just incorporated to preserve tenderness.
05 - In a separate bowl, combine molasses, brown sugar, melted butter, ground ginger, cinnamon, cloves, and nutmeg. Stir until the swirl mixture is uniform.
06 - Divide pumpkin batter among muffin cups, filling each about two-thirds full. Top each with a generous teaspoon of gingerbread swirl. Using a toothpick or skewer, gently swirl the two batters together for a marbled effect.
07 - Place the muffin tin in the oven and bake for 20–22 minutes, or until a toothpick inserted into the center of a muffin emerges clean.
08 - Allow muffins to cool in the tin for 10 minutes. Transfer to a wire rack and cool completely before serving or storing.