01 - Preheat oven to 350°F. Grease and flour a 9x5-inch loaf pan or line with parchment paper.
02 - In a large bowl, whisk together flour, sugar, baking powder, baking soda, cinnamon, and salt until well blended.
03 - In a separate bowl, whisk milk, eggs, melted butter, oil, and vanilla extract until smooth and uniform.
04 - Pour wet mixture into dry ingredients. Stir gently until just combined, being careful not to overmix.
05 - Transfer batter to prepared loaf pan, spreading evenly and smoothing the top surface.
06 - Bake for 45-55 minutes until a toothpick inserted into the center emerges clean.
07 - Let bread rest in pan for 10 minutes, then carefully remove to a wire rack.
08 - While bread remains warm, brush top with melted butter. Combine cinnamon and sugar in a small bowl, then sprinkle evenly over buttered surface.
09 - Allow to cool completely for clean slices, or serve slightly warm for optimal donut-like texture.