Strawberry Rhubarb Crumble Cake

​Heat the oven (with the oven rack in the middle) to 350°F. Spray a 9-inch round cake pan with removable bottom or a springform pan with cooking spray.

For the crumble, in a small bowl, combine the flour, granulated sugar, brown sugar, cardamom, and salt. Stir in the melted butter until large crumbs form. Put into the freezer while you make the cake.

For the cake, in a medium bowl, combine the rhubarb, strawberries, and ¼ cup of the granulated sugar. Toss to combine then set aside.

In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. In a liquid measuring cup, measure the buttermilk then add the vanilla.

In a large bowl or the bowl of a stand mixer, use an electric mixer on medium-high speed to beat the butter until creamy. Add the remaining 1 cup sugar and beat until fluffy, about 1 minute. Add the eggs one at a time, beating well after each addition and scraping down the sides of the bowl as necessary. With the mixer on low speed, add half of the flour mixture. Then add the buttermilk mixture. Now add the remaining flour mixture. Mix until just incorporated but do not over mix. Scrape the batter into the prepared pan and smooth the top. Scatter the fruit (leaving any juices in the bowl) evenly over the top of the cake. Crumble the crumble over the top.

Bake until a toothpick inserted into the center comes out with a few moist crumbs attached, 42 to 48 minutes. Let cool on a wire cooling rack for 15 minutes. Run a knife around the cake to loosen it from the pan then unmold. Let cool completely.