01 - Preheat oven to 350°F. Thoroughly grease and flour a 9x5-inch loaf pan, or line with parchment paper for easy removal.
02 - In a large mixing bowl, whisk together the flour, granulated sugar, baking powder, baking soda, ground cinnamon, and salt until evenly distributed.
03 - In a separate bowl, whisk together the whole milk, eggs, melted butter, vegetable oil, and vanilla extract until completely smooth and incorporated.
04 - Pour the wet mixture into the dry ingredients. Fold gently with a spatula or wooden spoon until just combined—stop as soon as flour streaks disappear. Avoid overmixing to keep bread tender.
05 - Transfer batter to the prepared loaf pan, spreading evenly. Bake for 45-55 minutes until golden brown and a toothpick inserted into the center emerges clean.
06 - Allow bread to rest in the pan for 10 minutes before carefully removing to a wire cooling rack.
07 - While bread is still warm, brush the entire top surface generously with melted butter. Mix the ¼ cup sugar and 1 teaspoon cinnamon in a small bowl, then sprinkle evenly over the buttered surface.
08 - Let bread cool completely before slicing for clean, neat cuts. Alternatively, serve slightly warm for that fresh-from-the-bakery donut experience.