Preheat your oven to 350℉ and lightly grease a muffin tin so the muffins will pop out easily once baked. In a small bowl, mix together the sugar and cinnamon, this little mix is what gives the muffins that irresistible cinnamon swirl flavor. Set it aside while you work on the batter.

In a different bowl, mix the flour, baking powder, and salt until combined. Giving it a few extra swirls helps keep the muffins light and tender. In a larger bowl, combine the white sugar, brown sugar, milk, egg, oil, and vanilla extract. Whisk until smooth and slightly glossy; if your milk is cold, warming it just a bit helps everything blend nicely.

Carefully fold the dry ingredients into the wet, stopping when most of the flour is incorporated, a few streaks are okay. Overmixing can make the muffins tough, and we want soft, tender bites. To layer, spoon some batter into each muffin cup, sprinkle a pinch of the cinnamon-sugar mix, then add a bit more batter and finish with another tiny sprinkle of cinnamon sugar. This creates those beautiful cinnamon spots inside.

Let them bake for about 17 minutes, or until a toothpick poked into the middle comes out clean. Watch the last few minutes carefully, you want the tops lightly golden but not overdone. Cool the muffins in the tin for several minutes before removing them with care.

To make the glaze, mix the powdered sugar with the heavy cream until silky smooth. For easy drizzling, pour it into a small plastic bag, snip a tiny corner, and decorate each muffin with playful zigzags or swirls. Don’t worry about perfection, it’s all part of the fun.