2packages 8 ounces each cream cheesesoftened to room temperature
1/2cupgranulated sugar
1large egg
Streusel Topping
1cupunsalted buttermelted (see notes if using salted butter)
1cuppacked light brown sugar
1/4cupgranulated sugar
3cupsall-purpose flour
2teaspoonsground cinnamon
1/4teaspoonkosher salt
Instructions
Preheat the Oven: Preheat oven to 325°F. Grease a 9x13-inch baking dish with nonstick spray or line with parchment paper for easier slicing.
Make the Cake Batter: In a large mixing bowl, cream together 12 tablespoons unsalted butter, 3/4 cup granulated sugar, and 1/4 cup packed light brown sugar using a hand or stand mixer on medium speed until light and fluffy, about 2 minutes. Add 3 large eggs, 1/3 cup whole milk, 1/3 cup sour cream, and 1 tablespoon pure vanilla extract; beat until smooth.
Add Dry Ingredients: Sprinkle 2 1/3 cups all-purpose flour evenly over the top of the wet mixture, then add 3/4 teaspoon baking powder, 1/2 teaspoon baking soda, 1/2 teaspoon ground cinnamon, and 1/4 teaspoon kosher salt directly on top. Mix on low just until combined. Do not overmix.
Layer the Cake: Spread half of the cake batter evenly in the prepared baking dish, using an offset spatula to smooth the surface.
Prepare the Cream Cheese Filling: In another mixing bowl, beat 2 packages 8 ounces each cream cheese, 1/2 cup granulated sugar, and 1 large egg together on medium-high speed for 2–3 minutes, until light, creamy, and smooth. Spread evenly over the first layer of cake batter.
Add the Final Cake Layer: Dollop the remaining batter over the filling and gently spread it out with a spatula to cover completely.
Make the Streusel Topping: In a medium bowl, whisk together 1 cup unsalted butter, 1 cup packed light brown sugar, and 1/4 cup granulated sugar. Add 3 cups all-purpose flour, and 2 teaspoons ground cinnamon, 1/4 teaspoon kosher salt then stir with a fork until the mixture is crumbly and evenly moistened. Sprinkle evenly over the top of the cake.
Bake the Coffee Cake: Bake for 43–48 minutes, or until the edges are golden and the top is set. A toothpick inserted halfway into the cake layer (not all the way to the cream cheese center) should come out clean.
Cool Before Slicing: Place the pan on a wire rack and cool for at least 30 minutes before cutting. If sliced too soon, the cream cheese layer will not be set and the cake may fall apart.
Notes
Storage: Store leftovers in an airtight container at room temperature for up to 2 days or in the refrigerator for up to 5 days.Freezing: Wrap slices individually or the whole cake tightly in plastic wrap, then foil. Freeze for up to 2 months. Thaw in the refrigerator overnight and warm in the microwave for 15–20 seconds to serve.Reheating: For a freshly-baked texture, reheat slices in a 300°F oven for 8–10 minutes, or microwave briefly just until warm.Ingredient Notes:If using salted butter, reduce added salt to 1/8 teaspoon in the cake and 1/8 teaspoon in the streusel.Room temperature ingredients blend better and yield a more tender crumb — cold ingredients cause curdling and dense cake.The cream cheese layer will remain slightly soft even when fully baked — don’t overbake trying to make it firm.