Full of citrus flavor, this recipe includes orange zest, sour cream, poppy seeds, and vanilla paste in the batter and orange juice in the luscious, easy icing. To serve, shower with more poppy seeds and get creative when cutting: Small and large planks, slices on the bias, and even triangles are fair game when it comes to a sheet cake.

Martha Stewart Living, January/February 2021


Credit: Con Poulos

Recipe Summary

20 mins
2 hrs 20 mins
Serves 10 to 12




Instructions Checklist
  • Cake: Preheat oven to 350°F. Brush a 9-by-13-inch or 8-by-12-inch baking pan with butter. Line with parchment, leaving a 2-inch overhang on long sides. Butter parchment.

  • Whisk together flour, baking powder, and salt. Combine eggs and sugar in the bowl of a mixer fitted with the whisk attachment. Beat on high speed until thick and pale, about 4 minutes. Add flour mixture; beat to combine. Add butter, zest, poppy seeds, and vanilla; beat to combine. Add sour cream; beat until smooth.

  • Scrape batter into prepared pan, smoothing top with a spatula. Bake until top springs back when lightly touched and a tester inserted in center comes out clean, 30 to 35 minutes (for 9-by-13-inch) or about 40 minutes (for 8-by-12).

  • Let cool in pan on a wire rack 10 minutes. Using parchment overhangs, lift cake out of pan and let cool completely on rack. (Cake can be made to this point and stored at room temperature, wrapped in plastic, up to 1 day.)

  • Icing: Whisk together confectioners' sugar, butter, and orange juice until smooth. Spread over cake. Sprinkle with poppy seeds. Let set at least 20 minutes before serving. Iced cake can be stored in an airtight container at room temperature up to 3 days.

Cook's Notes

Leftovers will last about three days at room temperature in an air-tight container.