Preheat and prepare pan. Position a rack in the center of your oven and preheat the oven to 350°F (177°C). Spray a 9”x5” loaf pan with cooking spray, or line with parchment paper and then spray with cooking spray.
Make crumble topping. In a small bowl, whisk together flour, sugar, brown sugar, and cinnamon. Stir in melted butter until a crumbly mixture is formed. Set aside. ½ cup + 2 tablespoons (75 g) all-purpose flour ¼ cup (50 g) granulated sugar ¼ cup (53 g) packed light brown sugar 1 teaspoon ground cinnamon 4 tablespoons (1/2 stick, 57 g) unsalted butter
Combine dry ingredients. In a mixing bowl, whisk together all-purpose flour, baking powder, and salt. Set aside. 2 cups (240 g) all-purpose flour 1 tablespoon baking powder ½ teaspoon salt
Combine wet ingredients. In a second mixing bowl, whisk together granulated sugar, brown sugar, eggs, sour cream, oil and vanilla until evenly combined. ½ cup (100 g) granulated sugar ½ cup (107 g) packed light brown sugar 2 large eggs ⅔ cup (152 g) sour cream ½ cup (120 ml) neutral-tasting oil 2 teaspoons vanilla extract
Combine wet and dry ingredients. Add the dry ingredients to the wet ingredients and mix together with a spatula or wooden spoon just until just combined. Fold in diced peaches. Do not overmix. 1 ½ cups peeled, diced peaches
Bake. Spoon batter into prepared loaf pan. Top with crumble topping. Bake in a preheated 350oF (177oC) oven for 55-65 minutes until a toothpick inserted into the middle of bread comes out clean or with a few moist crumbs clinging to it (no wet batter) and top springs back to the touch when lightly touched. Remove from the oven and cool completely in the pan on a wire cooling rack.
Make glaze. In a small bowl, stir together the powdered sugar, milk and vanilla. If glaze is too thick, add an additional tablespoon of milk. If glaze is too thin, add additional powdered sugar. Drizzle over cooled bread before serving. 1 cup 120 g powdered sugar 1--2 tablespoons milk ½ teaspoon vanilla extract