1-Getting started: Begin by preheating your oven to 350°F to ensure even baking right from the start. In the meantime, gather your ingredients and prepare the crumb topping by mixing ½ cup all-purpose flour, ¼ cup granulated sugar, 2 tablespoons packed brown sugar, ¾ teaspoon ground cinnamon, 1½ teaspoons espresso powder, and a pinch of salt. Add 4 tablespoons of chilled and cubed unsalted butter, working it in until you get pea-sized pieces, then chill it in the refrigerator.

2-Swirl preparation: Simply mix ⅓ cup packed brown sugar with 1 teaspoon espresso powder and set it aside for later.

3-Cake batter: Combine 1⅔ cups spooned and leveled all-purpose flour, 2 teaspoons baking powder, and ¼ teaspoon salt in one bowl. In another bowl, beat 4 tablespoons softened unsalted butter with ¾ cup granulated sugar until smooth. Add 2 large room-temperature eggs one at a time, then stir in 2 teaspoons pure vanilla extract and ⅓ cup sour cream.

4-Combining batter: Gradually add half the flour mixture to the wet ingredients, followed by ½ cup room-temperature brewed black coffee, and then the rest of the flour mixture.

5-Baking: Grease an 8×8-inch metal baking pan and pour in half the batter. Sprinkle the swirl mixture over it, add the remaining batter, and use a knife to create swirls in a figure-eight motion. Top with the crumb mixture and bake for 33 to 37 minutes, or until a toothpick comes out clean.

6-Finishing touches: Once baked, cool the cake completely on a wire rack before preparing the glaze by whisking 1¼ cups powdered sugar, 2 tablespoons brewed black coffee or milk, ½ teaspoon espresso powder, and ⅛ teaspoon vanilla extract until smooth, then drizzle it over the cake.