Lemon coffee cake adds a delicious twist to the classic coffee cake with buttery streusel topping by including a zesty lemon curd, cream cheese layer, and drizzle of sugar glaze!
Grease a glass 10” x 15” baking dish or a DEEP 9” x 13” baking dish. Set aside.
In a mixing bowl, beat together butter and cream cheese until creamy (about 2-3 minutes).
Add in brown sugar and white sugar. Beat until fluffy (about 2-3 minutes).
Beat in both eggs until combined.
Beat in vanilla extract until combined.
In a separate bowl, stir together flour, baking soda, baking powder, cornstarch and salt.
Slowly beat in a third of the dry mixture into the wet then add in half the buttermilk. Then beat in another third of the dry mixture and the rest of the buttermilk. Then beat in the remaining dry mix into the wet. Beat just until combined – do not over mix.
Pour half the batter into the prepared baking dish. The batter will be thick.
Spread the lemon curd carefully over the batter in the baking dish. Leave about ¾” space between the lemon curd and the edge of the pan. Lemon curd that spreads to the outside of the pan will burn while baking. Carefully top with the remaining batter, working from the outer perimeter towards inner to make sure that the lemon curd stays contained within the batter layers.
In a medium mixing bowl or the bowl of a standing mixer, beat together the cream cheese filling ingredients: cream cheese, sugar, egg, lemon zest, and lemon juice. Spread the cream cheese layer over the top layer of batter.
Whisk together flour, brown sugar, sugar, and cinnamon until well combined. Stir in melted butter with a fork until it is a crumbly mixture and there is no more visible white flour. Sprinkle over top of cake.
Bake cake for 60-75 minutes or until the center is set and no longer jiggles. COVER the coffee cake with aluminum foil after the first 20-30 minutes of baking to prevent the top from burning while the layers underneath cook through. Let the cake cool before adding glaze.
Stir together powdered sugar and milk. Drizzle over top of completely cooled cake.