Coffeecake < Tested — Blueprint >

Mix the brown sugar, flour, and cinnamon. Cut in the cold butter with a fork until the mixture is clumpy and crumbly. Sprinkle it generously over the batter [13, 43].

In a separate bowl, whisk the egg, sour cream, milk, melted butter, and vanilla until smooth [13, 43]. coffeecake

Use a box of yellow cake mix, 1 cup of sour cream, 3 eggs, and ½ cup of vegetable oil for a faster prep [11]. Mix the brown sugar, flour, and cinnamon

Bake for 30–35 minutes, or until a toothpick inserted in the center comes out clean [13, 43]. In a separate bowl, whisk the egg, sour

Preheat your oven to 350°F (175°C) and grease an 8-inch square baking pan [13, 43].

Watch this step-by-step guide to achieving the perfect moist crumb and crunchy topping for your coffee cake: Cinnamon Crumb Coffee Cake Recipe Amateur Investigator YouTube• Apr 26, 2026

This recipe features a moist, buttery base with a thick, crunchy streusel topping. For the Cake: Flour: 1 ½ cups all-purpose flour [13, 19, 43] Sugar: ½ cup granulated sugar [13, 19, 43] Leavening: ½ tsp baking soda and ½ tsp salt [13, 43]