Preheat your oven to 350°F (175°C) and grease a 9x5-inch loaf pan.
In a large mixing bowl, whisk together the flour, sugar, baking powder, cinnamon, and salt until well combined.
In another bowl, mix the milk, eggs, melted butter, and vanilla extract until smooth.
Pour the wet ingredients into the dry ingredients and stir until just combined. Do not overmix; a few lumps are okay.
Pour the batter into the prepared loaf pan and smooth the top with a spatula.
Bake for 50-60 minutes, or until a toothpick inserted into the center comes out clean.
While the bread is baking, prepare the topping by mixing the sugar and cinnamon in a small bowl.
Once the bread is done, remove it from the oven and let it cool in the pan for about 10 minutes.
Carefully remove the bread from the pan and brush the top with melted butter, then sprinkle the cinnamon-sugar mixture evenly over the top.
Allow the bread to cool completely on a wire rack before slicing.