This plum cake comes out tall, tender, and so juicy that it barely lasts a day in my house. What I love about it is that some of the plums go right into the batter while the rest go on top, all covered in a buttery cinnamon streusel that bakes into the crispiest, most fragrant crumb. It’s a simple fall cake that doesn’t even need a mixer, and it’s absolutely perfect with a cup of coffee or tea on a cool afternoon.
For the batter:
- 4 eggs
- ¾ cup plus 1 tablespoon granulated sugar
- 2 teaspoons vanilla extract
- 1½ to 1⅔ cups all-purpose flour
- 2 teaspoons baking powder
- pinch of salt
For the filling:
- 1 lb plums
For the streusel:
- 3½ tablespoons unsalted butter, softened
- ½ cup plus 1 tablespoon all-purpose flour
- ¼ cup granulated sugar
- 1 teaspoon vanilla extract
- ¼ to ½ teaspoon ground cinnamon
Crack the eggs into a large bowl. Add the sugar, vanilla, and a pinch of salt, and whisk until the mixture is pale and a little foamy. You don’t need a mixer for this recipe at all, a whisk does the job just fine.
Combine the flour with the baking powder and sift it into the egg mixture in a few additions, gently folding it in with a whisk or spatula until smooth. The finished batter should be about the consistency of thick sour cream and slowly ribbon off the whisk. Start with 1½ cups of flour, and if it’s still too thin, add a little more.
Wash and dry the plums, remove the pits, and cut each half into two, three, or four pieces depending on how big they are. Fold about half the plums gently into the batter so the pieces are evenly distributed.
For the streusel, mix the flour, sugar, vanilla, and cinnamon together in a separate bowl. Add the softened butter and rub everything together with a spoon or your fingers until it forms coarse crumbs. Pop the streusel in the fridge while you assemble the cake.
Line a 9-inch round pan with parchment paper. To help the paper lie flat against the sides, you can lightly wet it, crumple it, then smooth it back out. Grease the parchment and the sides of the pan with a little oil.
Pour the plum batter into the pan and smooth it out. Scatter the remaining plum pieces evenly over the top, then sprinkle the chilled streusel crumbs all over.
Bake in a preheated 350°F oven for about 45 to 50 minutes. Use the regular top-and-bottom bake setting without convection. The exact time depends on your oven and how juicy the plums are.
Check it with a toothpick, it should come out dry from the center. If the top is browning nicely but the middle isn’t done yet, tent the pan loosely with foil and keep baking.
Let the cake sit in the pan for 10 to 15 minutes, then carefully remove it and cool it on a wire rack. It comes out soft and juicy on the inside with that gorgeous fragrant, crunchy crumb on top.