Preheat oven to 350°F (180°C). Grease an 8-inch round deep cake pan with baking spray or butter and dust with flour.

Browned Butter: In a medium saucepan, melt butter over medium heat. Cook until butter turns a medium-brown color and has a nutty aroma, about 10 minutes. Remove from heat, and let cool to room temperature.

Streusel: In a medium bowl, whisk together flour, brown sugar, cinnamon, and salt. Stir in butter until mixture is crumbly. Crumble with your fingertips until desired consistency is reached. Stir in pecans.

Cake: In the bowl of a stand mixer fitted with the paddle attachment, beat eggs, banana, pineapple, and vanilla at medium speed until combined, 1 to 2 minutes. Stir in browned butter.

In a medium bowl, whisk together flour, ¾ cup (150 grams) granulated sugar, brown sugar, salt, baking powder, and ½ teaspoon (1 gram) cinnamon. Gradually add flour mixture to browned butter mixture, beating just until combined.

In a small bowl, stir together remaining 1 tablespoon (12 grams) granulated sugar and remaining ½ teaspoon (1 gram) cinnamon. Spread half of batter into prepared pan. Sprinkle with one-third of streusel and cinnamon-sugar mixture. Top with remaining batter, smoothing top with an offset spatula. Sprinkle with remaining streusel.

Bake until a wooden pick inserted in center comes out clean, 45 to 50 minutes, loosely covering with foil to prevent excess browning, if necessary. Let cool in pan the 15 minutes. Run a sharp knife around edges of cake to loosen sides. Invert onto a plate, and then invert again onto a wire rack.

Glaze: In a small bowl, whisk together confectioners’ sugar, sour cream, and milk. Pour over warm cake.