01 -
Preheat the oven to 175°C. Grease a loaf pan with nonstick baking spray and line the base with parchment paper. Set aside.
02 -
In a small bowl, combine 1/3 cup granulated sugar with ground cinnamon. Stir until well mixed, then set aside.
03 -
In a large mixing bowl, whisk together flour, baking powder, salt, and 1 cup granulated sugar until evenly incorporated. Set aside.
04 -
In a separate bowl, whisk egg, milk, and vegetable oil until fully blended. Pour the wet mixture into the bowl with dry ingredients. Stir gently with a rubber spatula until just moistened, avoiding overmixing. Fold in the chopped rhubarb.
05 -
Spoon half the batter into the prepared loaf pan; spread evenly. Sprinkle half the cinnamon sugar mixture over the batter. Repeat with remaining batter and cinnamon sugar on top. If desired, gently swirl the topping into the batter for a marbled effect.
06 -
Transfer the pan to the preheated oven and bake for approximately 60 minutes, or until a toothpick inserted in the center comes out clean. Place the pan on a wire rack and allow to cool for 10 minutes. Remove the bread from the pan and let it cool completely. For optimal slicing, wrap the cooled loaf in plastic wrap and refrigerate for several hours before serving.