Preheat and prep: Heat the oven to 375°F (190°C). Lightly grease a 24-cup mini muffin pan or line with mini paper liners. If greasing, use a thin coat to help the sugar coating stick later.

Mix dry ingredients: In a medium bowl, whisk 1 1/2 cups all-purpose flour, 1/2 cup granulated sugar, 1 1/2 teaspoons baking powder, 1 teaspoon ground cinnamon, 1/4 teaspoon salt, and 1/4 teaspoon cream of tartar (if using) until evenly combined.

Combine wet ingredients: In a separate bowl, whisk 1/2 cup whole milk, 1 large egg, 1 teaspoon vanilla extract, and 1/4 cup melted unsalted butter (slightly cooled so it doesn’t cook the egg).

Make the batter: Pour the wet mixture into the dry ingredients and stir gently with a spatula until just combined. Do not overmix. The batter should be thick and slightly lumpy.

Fill the pan: Spoon the batter into the mini muffin cups, filling each about 3/4 full. A small cookie scoop makes this easy and even.

Bake: Bake for 10–12 minutes, or until the tops spring back lightly and a toothpick inserted in the center comes out clean or with a few moist crumbs.

Cool briefly: Let the muffins cool in the pan for 2 minutes, just until they’re cool enough to handle but still warm. Warm muffins grab the coating better.

Prepare the coating: In a small bowl, mix 1/2 cup granulated sugar with 1 1/2 teaspoons ground cinnamon. In another small bowl, melt 3 tablespoons unsalted butter.

Coat the muffins: One at a time, dip each warm muffin top (or the whole muffin) in melted butter, then roll or toss in the cinnamon-sugar. For extra coverage, double-dip: butter, sugar, butter, sugar.

Serve: Enjoy warm for the best texture and aroma. They’re at their peak right after coating.