Preheat your oven to 180°C (350°F) and line a muffin tin with paper liners or grease it well. Gather your ingredients for easy assembly.
In a large mixing bowl, whisk together the sifted flour, sugar, cinnamon, and baking powder until evenly combined. This creates a fragrant dry base.
In a small saucepan, melt the butter over low heat, then let it cool slightly so it doesn't cook the eggs later.
In a separate bowl, whisk the eggs, milk, and melted butter together until smooth and slightly frothy, about 30 seconds.
Pour the wet mixture into the dry ingredients and gently fold with a spatula until just combined; be careful not to overmix, leaving some lumps for a tender crumb.
Divide the batter evenly among the muffin cups, filling each about two-thirds full. The batter should be slightly thick but scoopable.
In a small bowl, mix together the extra cinnamon and sugar for the topping. Sprinkle generously over each filled muffin, creating a crackly sugar crown.
Bake the muffins in the preheated oven for 20 to 25 minutes, or until the tops are golden brown and a toothpick inserted into the center comes out clean. The sweet aroma of cinnamon will fill your kitchen as they bake.
Remove the muffins from the oven and let them cool in the tin for about 5 minutes. Then, transfer them to a wire rack to cool slightly, allowing the sugar top to set and crackle.
Serve these warm or at room temperature, enjoying that irresistible cinnamon scent and tender, moist crumb with a crispy, caramelized sugar crust on top.
