Easy Coffee Cake

Cake and assembly

Step 2

Whisk ½ cup (100 g) granulated sugar، 2 Tbsp. all-purpose flour، and 1 Tbsp. ground cinnamon in a medium bowl to combine. Set sugar mixture aside.

Step 3

Whisk ¾ cup (1½ sticks) unsalted butter، melted، slightly cooled، and remaining 2 cups (400 g) granulated sugar in a large bowl until smooth. Add 3 large eggs، room temperature، one at a time، whisking after each addition until fully incorporated before adding the next one. Add ⅔ cup sour cream، room temperature، and 1 Tbsp. vanilla extract and whisk until smooth. Gradually pour in 1⅓ cups whole milk، room temperature، whisking constantly until combined. Sift remaining 3¾ cups (469 grams) all-purpose flour، 1 Tbsp. baking powder، and 1 tsp. Diamond Crystal or ½ tsp. Morton kosher salt directly into bowl and mix just until a thick batter forms and all large pockets of flour are incorporated (some small lumps are okay).

Step 4

Scrape about half of batter into prepared baking pan and spread into an even layer with an offset spatula. Sprinkle reserved sugar mixture evenly over batter. Dollop remaining batter on top (a cookie scoop works well here) and carefully spread into an even layer with spatula. Sprinkle reserved streusel evenly over; gently press to adhere.

Step 5

Bake cake، rotating pan halfway through، until a tester inserted into the center comes out with just a few moist crumbs attached، 55–65 minutes. Let cake cool in pan before cutting into 18 squares.