Ingredients

¼ cup plus 2 tablespoons safflower oil, and more for pan
2 ¼ cups unbleached all-purpose flour
1 ½ cups granulated sugar
1 tablespoon plus ½ teaspoon baking powder
¾ teaspoon kosher salt
¾ teaspoon ground cinnamon
¼ teaspoon ground cardamom
1 large egg plus 1 large egg yolk, room temperature
¾ cup sour cream
2 ¼ teaspoons pure vanilla extract
4 ½ tablespoons whole milk, room temperature
¾ cup confectioners' sugar
1 vanilla bean, split and seeds scraped
1 ½ teaspoons to 1 tablespoon grated lemon zest, plus 1 to 3 tablespoons fresh juice

Directions

Preheat oven to 350°F. Brush a 9-by-13-inch baking pan with oil. Line with parchment, leaving a 2-inch overhang on two sides; brush parchment. In a large bowl, whisk together flour, granulated sugar, baking powder, salt, cinnamon, and cardamom.
In a medium bowl, whisk together egg and yolk, sour cream, oil, vanilla, and 3 tablespoons milk until combined. Add egg mixture to flour mixture; stir until smooth (batter will be thick). Transfer to prepared pan, smoothing top with an offset spatula.
Bake until lightly golden and top of cake springs back when lightly pressed, 35 to 40 minutes. Transfer pan to a wire rack; let cool 30 minutes. Using overhangs, transfer cake from pan to rack; let cool completely.
In a small bowl, whisk together confectioners' sugar, remaining 1 1/2 tablespoons milk, vanilla seeds, 1 1/2 teaspoons lemon zest (or up to 1 tablespoon, for a zesty bite), and 1 tablespoon lemon juice until smooth and pourable. (If glaze is too thick, add up to remaining 2 tablespoons lemon juice.)
Pour over top of cake, spreading to edges with offset spatula. Allow to set before slicing, about 30 minutes. Cake can be refrigerated, wrapped in plastic, up to 3 days; return to room temperature before serving.

Lennart Weibull

Cook's Notes

Recipes reprinted from: Martha Stewart’s Cookie Perfection: 100+ Recipes to Take Your Treats to the Next Level, From the Kitchens of Martha Stewart Living. Copyright © 2020 by Martha Stewart Living Omnimedia, Inc. Published by Clarkson Potter/Publishers, an imprint of Random House, a division of Penguin Random House LLC. Available October 13th wherever books are sold; to pre-order, go to amazon.com.