Grease and flour a 13x9 inch baking dish. In a bowl, beat flour, sugar, baking powder, baking soda, and salt on low speed to combine. Add softened butter and beat until mixture is crumbly. Beat in eggs, vanilla, and buttermilk until fluffy. Pour half of the batter into the baking dish and spread evenly.
In a separate bowl, beat cream cheese with 0.5 cup sugar and 1 egg until light and fluffy, about 3–5 minutes. Pour cream cheese mixture over the batter in the baking dish. Top with remaining half of cake batter.
For the topping, mix light brown sugar, granulated sugar, cinnamon, and salt. Add melted butter and blend well. Add flour and mix with hands until fully combined into a crumbly texture.
Sprinkle crumb topping evenly over the cake batter.
Bake the cake at 325°F for about 45 minutes or until a toothpick inserted in the center comes out clean. Cool completely before serving.
Notes
This cream cheese coffee cake keeps well for 2 days at room temperature or can be refrigerated for up to 5 days. It’s delicious served warm or at room temp.