¼ cup plus 2 tablespoons (85 grams) unsalted butter, melted
1½ teaspoons (6 grams) vanilla extract
2 cups (250 grams) all-purpose flour
1½ teaspoons (3 grams) ground cinnamon
½ teaspoon (2.5 grams) baking powder
½ teaspoon (1.5 grams) kosher salt
¼ teaspoon (1.25 grams) baking soda
½ cup (160 grams) blueberry jam, divided
Nut Streusel (recipe follow)
Sugar Glaze (recipe follows)
Instructions
Preheat oven to 350°F (180°C). Line an 8½x4½-inch loaf pan with parchment paper.
In a large bowl, whisk together brown sugar, sour cream, eggs, melted butter, and vanilla. In a medium bowl, whisk together flour, cinnamon, baking powder, salt, and baking soda. Add flour mixture to sugar mixture, whisking just until combined.
Spoon one-third of batter into prepared pan, spreading evenly. Top with ¼ cup (80 grams) jam, leaving a ¼-inch border. (Spread jam gently, so that it doesn't bleed into cake layer too much.) Spoon another one-third of batter over jam, spreading evenly. Top with remaining ¼ cup (80 grams) jam. Spoon remaining batter over jam, spreading evenly. Top with Nut Streusel.
Bake for 30 minutes. Cover with foil, and bake until a wooden pick inserted in center comes out clean, about 45 minutes more. Let cool in pan for 10 minutes. Remove from pan, and let cool completely on a wire rack. Drizzle with Sugar Glaze.
Notes
*We used sour cream, but you can also use the same measurement of buttermilk, crème fraîche, or yogurt.
Recipe by Bake from Scratch at https://bakefromscratch.com/cinnamon-jam-loaf/