Arrange a rack in center of oven; preheat to 350°. Grease a 9" x 5" loaf pan with cooking spray, then line with parchment, leaving a 2" overhang on 2 long sides.

In a small bowl, combine brown sugar, cinnamon, cocoa powder, and ¼ cup granulated sugar. Set aside until ready to use.

In a medium bowl, whisk flour, baking powder, salt and baking soda. In the large bowl of a stand mixer fitted with the paddle attachment (or in a large bowl using a handheld mixer), beat butter and remaining 1 cup granulated sugar on medium-high speed until light and fluffy, 2 to 3 minutes. Add eggs, one at a time, beating to blend after each addition. Add vanilla, scraping down bowl as needed.

Reduce speed to low. Add half of dry ingredients and beat until nearly incorporated. Add sour cream and beat until just combined. Beat in remaining dry ingredients.

Transfer one-third of batter to prepared pan; spread in an even layer. Sprinkle half of cinnamon-swirl mixture over. Repeat with another third of the batter and remaining cinnamon-swirl mixture. Top with remaining batter. Using the tip of a butter knife or skewer, gently swirl batter. Crumble cinnamon crunch topping over.

Bake bread until a tester inserted into the center comes out clean, 60 to 65 minutes. Transfer to a wire rack. Let cool 20 minutes.

Using parchment overhang, lift out bread and transfer to a cutting board. Remove parchment and let cool.

In a small bowl, combine confectioners’ sugar, sour cream, vanilla, and salt.

Drizzle glaze over bread, then cut into thick slices.