Ingredients
Scale
- For the Cake:
- 1 tablespoon finely grated grapefruit zest
- 1 cup granulated sugar
- 2 large eggs, at room temperature
- 1/3 cup unsalted butter, melted
- 1 teaspoon pure vanilla extract
- 1½ cups all-purpose flour
- 1 1/2 teaspoons baking powder
- 1/2 teaspoon baking soda
- ¾ teaspoon kosher salt
- ¾ cup plain whole milk Greek yogurt
- 5 tablespoons fresh grapefruit juice
- 1 tablespoon poppy seeds, plus more for sprinkling
- For the Glaze:
- ½ cup powdered sugar
- 1 tablespoons fresh grapefruit juice
- 1 tablespoon plain whole milk Greek yogurt
- pinch of salt
Instructions
- Place a rack in the upper third of the oven and preheat oven to 350°F.
- Grease an 8½x4½-inch loaf pan, preferably metal, with butter or non-stick baking spray. Line with parchment paper, leaving overhang on the long sides, and lightly coat the paper with nonstick spray as well. Set the pan aside.
- Place sugar in a medium bowl. Using your fingers, work grapefruit zest into granulated sugar until sugar starts to clump and mixture is very fragrant.
- Beat in the eggs, melted butter, and vanilla on medium speed until light and thick, about 4 minutes.
- In a small bowl, whisk flour, baking powder, baking soda, and salt.
- Reduce mixer speed to low and mix in half of dry ingredients, until just combined. Beat in the yogurt and grapefruit juice until combined. Mix in remaining dry ingredients followed by and 1 tablespoon poppy seeds. Scrape batter into prepared pan and smooth top.
- Bake cake until top is golden brown and a tester inserted into the center comes out clean, 50–60 minutes. Transfer pan to a wire rack.
- Whisk powdered sugar, remaining 1 tablespoon grapefruit juice and 1 tablespoon yogurt, and a pinch of salt in a medium bowl until smooth. Drizzle over cake. Sprinkle with poppy seeds and let sit until glaze is set, about 30 minutes.
- Enjoy at room temperature with hot coffee. To store the cake, keep it well wrapped at room temperature for up to 4 days.