• NOTE: if you are making the lemon curd from scratch, start with that first! It takes 2 to 4 hours to chill in the fridge. I suggest making it a day or two ahead of time.
• Preheat the oven to 350 degrees F. Spray a 9x9 inch baking dish with nonstick baking spray.

crumb

• Whisk together the flour, sugar, lemon zest and salt. Add the cold butter and rub it into the flour with your fingers. You want to combine it for a few minutes until the butter is throughout all the flour and the texture almost resembles sand.

cake

• In a bowl, stir together the flour, baking soda and salt.
• In the bowl of your electric mixer, beat the butter and sugar together on high speed until creamy, about 3 to 4 minutes. Beat in the egg yolks one at a time. Beat in the extracts and lemon zest until combined.
• Beat in half of the flour mixture until just combined. Beat in the greek yogurt. Beat in the remaining dry ingredients until just combined.
• In a bowl, beat the egg whites with an electric hand mixer until foamy. Gradually add in the 2 tablespoons of sugar, beating until stiff peaks form. Fold the egg white mixture into the cake batter.
• Spread the batter into the greased baking dish. Dollop the lemon curd on top and gently swirl it in with a knife.
• Sprinkle the crumb mixture all over the batter. Bake for 40 t0 45 minutes, or until a tester inserted in the center comes out clean. Remove from the oven and sprinkle the top with powdered sugar.

easy lemon curd (if you don’t buy it)

• Beat the butter and sugar in the bowl of your electric mixer until creamy. Add the eggs one at a time, beating until each is combined. Beat in the lemon zest. Stream in the lemon juice with the mixer on medium-low speed. The mixture will look curdled.
• Transfer the mixture to a microwave-safe bowl. Microwave for 5 minutes, stirring every 1 minute. Then microwave for 1 to 2 more minutes, stirring after each 30 second increment, until it coats the back of a spoon.
• Place a piece of plastic wrap over the bowl, pressing it directly into the curd. Refrigerate for 2 to 4 hours, or until chilled and thick.