Preheat oven to 325°F (170°C). Spray an 8½x4½-inch loaf pan with baking spray with flour. Line pan with parchment paper, letting excess extend over sides of pan.
For filling: In a small bowl, stir together flour, brown sugar, and cinnamon. Using your fingers, cut in butter until mixture is well combined and sandy.
For batter: In a medium bowl, whisk together flour, salt, baking soda, and baking powder.
In a large bowl, whisk together banana, brown sugar, oil, sour cream, eggs, melted butter, and vanilla bean paste. Gradually stir in flour mixture just until combined. Spread one-third of batter (about 1 cup or 280 grams) into prepared pan. Sprinkle with half of filling (about 2½ packed tablespoons or 30 grams), leaving a 1⁄8- to 1⁄4-inch border around edges. Spread one-third of batter on top of filling in pan, and sprinkle with remaining filling, leaving a 1⁄8- to 1⁄4-inch border around edges. Dollop remaining batter on top, and spread in an even layer. Sprinkle with Cinnamon Sugar Topping.
Bake for 40 minutes. Rotate pan, and bake until a wooden pick inserted in center comes out clean and an instant-read thermometer inserted in center registers 200°F (93°C) to 205°F (96°C), 26 to 32 minutes more, loosely covering with foil during final 10 to 12 minutes of baking to prevent excess browning. Let cool in pan on a wire rack for 10 minutes. Remove from pan, and let cool on wire rack for 10 minutes. Serve warm, or let cool completely.
Source: https://www.bakefromscratch.com/category/recipes/bread/feed/
