Lemon Poppyseed Sheet Cake

Sheet cake is the perfect thing for your more casual cake occasions, especially when you need cake for a lot of people. While I love an elegant layer cake, I have a special fondness for cake that’s quick and unfussy, just like this Lemon Poppyseed Sheet Cake. If you’re a frosting fan, you’ll appreciate the cake to frosting ratio here and everyone can appreciate the sweet but tart lemon flavor.

The batter for this cake is a little different than most, in that you boil some water, butter, and shortening together before mixing the liquid into the flour and sugar. There’s also buttermilk involved, so while it’s a thin cake, it’s a very moist one.

And there are plenty of poppyseeds. Plenty. You’ll taste their sweet little pop in every bite, guaranteed.

The frosting relies on a stovetop preparation as well, but you can do it while the cake bakes – it’s just a matter of boiling some butter and milk before whisking in some powdered sugar and lemon juice.

The lemon flavor is certainly noticeable, but it’s not overwhelming, and poking some holes all over the warm cake before you pour the frosting over the top helps it seep down into the crumb a bit.

It’s the type of cake that you might turn to because it’s so easy to make, but you find yourself coming back to it because it’s just so delicious. It’s a cinch, but it’s a scrumptious and sunny one.

Lemon Poppyseed Sheet Cake

30 minutes to prepare serves 12


  • 2 cups all-purpose flour
  • 1 1/2 cups granulated sugar
  • 1/2 cup (1 stick) unsalted butter
  • 1 cup water
  • 1/2 cup shortening
  • 1/2 cup buttermilk
  • 1/2 teaspoon baking soda
  • 2 eggs
  • 1 teaspoon vanilla
  • 1 teaspoon lemon extract
  • Zest of 2 lemons
  • 1 1/2 tablespoon poppy seeds
  • For the icing:
  • 1/2 cup (1 stick) unsalted butter
  • 1/4 cup milk
  • 3 cups powdered sugar
  • Juice from one lemon


  1. Preheat oven to 400°F and grease a jelly roll pan (about 10x15-inch) with butter or nonstick spray.
  2. In a large bowl, whisk together the flour and sugar. Set aside.
  3. To a medium saucepan, add the butter, water, and shortening. Bring to a boil. Once bubbling, pour into flour mixture and stir to combine.
  4. Add the buttermilk, followed by the baking soda, eggs, vanilla, lemon extract, lemon zest, and poppyseed, stirring in between each addition.
  5. Pour batter into prepared pan and bake until a toothpick inserted into the center comes out clean, about 20 minutes.
  6. To make the icing, bring the butter and milk to a boil in a medium saucepan. Add powdered sugar and lemon juice and stir until smooth.
  7. While cake is still warm, poke all over with a fork and pour icing evenly over the top.
  8. Let cool before slicing and serving. Enjoy!

Recipe adapted from The Loopy Whisk.

Whizzco for LPE