Lemon-Cheesecake Streusel Squares

• MAKE-AHEAD
• VEGETARIAN

Cake

1. 2 cups all-purpose flour
2. 3/4 cup sugar
3. 2 1/2 teaspoons baking powder
4. 1/2 teaspoon baking soda
5. 1/4 teaspoon salt
6. 1/2 cup vegetable oil
7. 1 large egg
8. 1/2 cup milk
9. 3 tablespoons fresh lemon juice
10. 1/2 teaspoon finely grated lemon zest

Swirl

1. 6 ounces cream cheese, softened
2. 1 large egg yolk
3. 1/4 cup sugar
4. 1 tablespoon fresh lemon juice
5. 1/2 teaspoon finely grated lemon zest

Crumble

1. 1/2 cup all-purpose flour
2. 2 tablespoons sugar
3. 2 tablespoons unsalted butter, softened
4. Salt

1. MAKE THE CRUMBLE Preheat the oven to 350°. Butter a 9-inch square baking pan. In a large bowl, whisk the flour with the sugar, baking powder, baking soda and salt. In a small bowl, combine the oil, whole egg, milk, lemon juice and zest. Using an electric mixer, beat the wet ingredients into the dry ingredients just until they're evenly moistened. Scrape the batter into the pan.
2. In a medium bowl, beat the cream cheese with the egg yolk, sugar, lemon juice and zest. Spoon the cheesecake mixture onto the batter in clumps and gently swirl three times with a table knife.
3. In a small bowl, combine the flour and sugar with the butter and a pinch of salt. Press into clumps and sprinkle over the batter. Bake for 45 to 50 minutes, until the loaf is golden and risen and a toothpick inserted in the center comes out with a few moist crumbs attached. Transfer the pan to a rack and let cool for 30 minutes, then cut the cake into squares and serve.