A simple cake made with buttermilk (for a moist, tender crumb) is a perfect foil for juicy, sweet-tart plums or pluots. The dessert is best served warm with a slathering of delicious Honey Cream or ice cream, if you prefer. The cake will keep for 1 day, covered and refrigerated.
Position a rack in the middle of the oven and preheat to 350 degrees F. Butter an 11x7-inch baking pan and set aside.
Place the flour, almond flour, sugar, baking powder, and salt in a food processor and process until combined. Add the butter, eggs, buttermilk, vanilla, and lemon zest and pulse until the mixture is just combined. Don’t overprocess.
Spread the batter in the prepared pan. Arrange the plum halves on top, cut side up, pressing the fruit lightly into the batter. Drizzle the plums with the honey and sprinkle with the almonds.
Bake until the cake is set and a toothpick inserted into the center of the cake comes out clean, about 40 minutes. Cool on a wire rack for at least 15 minutes.
To make the honey cream, place the cream, yogurt, and honey in a mixing bowl and beat until the cream forms soft peaks.
To serve, slice the cake and serve with a generous dollop of the honey cream.