Lemon-Yogurt Crumb Cake

Ingredients

• 0.1 teaspoon baking soda 
• 0.5 cup butter cold cut into pieces
• 0.5 cup butter softened
• 3 large eggs separated
• 1.5 cups flour all-purpose
• 0.7 cup granulated sugar 
• 1.5 cups granulated sugar divided
• 0.8 cup easy lemon curd quick
• 1 tablespoon lemon zest 
• 1 tablespoon orange zest 
• 0.5 cup greek yogurt plain
• 0.3 cup powdered sugar 
• 0.1 teaspoon salt 
• 10 servings crumb topping 

Equipment

• frying pan
• oven
• knife
• wire rack
• blender
• stand mixer

Directions

1. Prepare Crumb Topping: Preheat oven to 35
2. Combine first 5 ingredients; cut cold butter into flour mixture with a pastry blender or fork until crumbly. Cover and chill until ready to use.
3. Prepare Cake Batter: Beat softened butter at medium speed with a heavy-duty electric stand mixer until creamy.
4. Add 1 1/4 cups granulated sugar, beating 3 minutes or until fluffy.
5. Add egg yolks, 1 at a time, beating just until yellow disappears.
6. Stir together flour and baking soda; add to butter mixture alternately with yogurt, beginning and ending with flour mixture. Stir in lemon zest.
7. Beat egg whites at high speed until foamy; gradually add remaining 1/4 cup granulated sugar, 1 Tbsp. at a time, beating until stiff peaks form. Fold into batter.
8. Pour batter into a greased and floured 9-inch square (2-inch-deep) pan. Dollop with lemon curd; gently swirl with a knife.
9. Sprinkle Crumb Topping over batter.
10. Bake at 350 for 45 to 50 minutes or until a wooden pick inserted in center comes out clean.
11. Remove from oven; dust with powdered sugar.
12. Serve warm, or cool on a wire rack 1 hour.