Preheat oven and line tin:
Heat oven to 375°F (190°C). Place paper liners in a 12-cup muffin tin.Mix cinnamon-sugar topping:
Combine 1 tablespoon granulated sugar with 1 teaspoon ground cinnamon in a small bowl; reserve for topping.Whisk wet ingredients:
Whisk 3/4 cup granulated sugar, yogurt, melted butter, eggs, and vanilla in a large bowl until smooth.Stir in dry ingredients:
Stir baking powder, baking soda, salt, and the remaining 1 tablespoon cinnamon into the wet mixture until blended.Fold in flour:
Fold in flour gently until just combined (avoid overmixing).Fill cups and add topping:
Evenly distribute batter among muffin cups. Top each with the cinnamon-sugar mixture.Bake until golden:
Bake for 18-20 minutes, or until a toothpick inserted into the center comes out clean.Cool in pan then rack:
Let cool in the pan for 5 minutes, then move to a wire rack to cool fully.