Grapefruit Upside-down Cake

Ingredients

• 2 large pink grapefruit – peeled, segmented (membranes and pith removed), patted dry
• 4 tbsp unsalted butter – melted for pan
• 0.5 cup light brown sugar
• 1.5 cups all-purpose flour
• 1.5 tsp baking powder
• 0.25 tsp baking soda
• 0.5 tsp kosher salt
• 8 tbsp unsalted butter – softened
• 0.75 cup granulated sugar
• 2 large egg – at room temperature
• 1 tsp vanilla extract
• 0.25 cup grapefruit juice – freshly squeezed
• 0.5 cup buttermilk – at room temperature
• whipped cream – for serving

Instructions

1. Preheat the oven to 350°F (175°C). Set a 9-inch round cake pan (2 inches deep) on a baking sheet to catch any drips.
2. Prep the fruit: Using a sharp knife, cut the ends off 2 large pink grapefruits, remove the peel and all white pith, and cut out the segments over a bowl to catch juice; lay the segments on paper towels and pat dry.
3. Make the pan base: Put 4 tbsp unsalted butter in the cake pan and place it in the oven until melted, 2–3 minutes. Swirl to coat the bottom, sprinkle evenly with 0.5 cup light brown sugar, and return to the oven until the sugar looks wet and bubbly at the edges, 3–5 minutes.
4. Arrange the prepared segments snugly over the melted sugar in a single layer, covering the bottom.
5. In a medium bowl, whisk together 1.5 cups all-purpose flour, 1.5 tsp baking powder, 0.25 tsp baking soda, and 0.5 tsp kosher salt.
6. In a large bowl, cream 8 tbsp unsalted butter (softened) with 0.75 cup granulated sugar using a mixer on medium speed until pale and fluffy, 2–3 minutes.
7. Beat in 2 large eggs one at a time, then mix in 1 tsp vanilla extract, scraping the bowl as needed.
8. Stir together 0.5 cup buttermilk and 0.25 cup grapefruit juice (freshly squeezed).
9. Add the dry ingredients to the butter mixture in three additions, alternating with the buttermilk mixture and beginning and ending with dry. Mix on low just until the batter is smooth; do not overmix.
10. Dollop the batter over the fruit and gently spread it to the edges in an even layer.
11. Bake until the top is golden and a toothpick inserted in the center comes out clean or with a few moist crumbs, 35–45 minutes.
12. Cool the cake in the pan on a rack for 10 minutes. Run a thin knife around the sides, invert a serving plate over the pan, and flip; lift off the pan. If any fruit sticks, loosen and return it to the top.
13. Serve warm or at room temperature with whipped cream, if desired.