3 medium navel or cara cara oranges (you need 1 1/2 cups of ground oranges so maybe 2 oranges will do if they’re on the large side. Thin skins are key.)
1 cup (2 sticks) unsalted butter, softened to room temperature
1 2/3 cups granulated sugar
4 large eggs
1 tablespoon pure vanilla extract
1/4 cup sour cream
lightly whipped whipped cream, for serving
Place a rack in the middle of the oven and preheat oven to 350 degrees F.
Grease a bundt pan with butter, shortening, or nonstick baking spray. Grease every nook and cranny. Dust generously with flour and knock the excess flour out of the pan. Set aside.
Let’s first make the crumble. In a medium bowl stir together flour, brown sugar, spice, and salt. Add the butter and use your fingers to your the butter into the dry mixture, creating a crumble. Set aside.
In a medium bowl, whisk together flour, baking powder, baking soda, and salt. Set aside.
Now let’s grind up the oranges. Chop whole oranges into 2-inch chunks – peel and all! You’ll want to use oranges that don’t have a very thick peel and pith. Choose oranges that have a thinner peel and are relatively seedless.
Place the oranges in the bowl of a food processor fitted with the blade attachment. Place the lid on the food processor, and pulse a few rounds to start.
Process the oranges on low speed until the peel, flesh and juice begin to meld, creating a well ground, thick orange mixture. The mixture won’t be completely smooth. It’s ok if there are small pea size chunks of peel in the mixture. Spoon mixture into a glass measuring cup and measure 1 1/2 cups ground orange to use in the cake. Set aside the measured orange mixture.
In the bowl of a stand mixer fitted with a paddle attachment, place softened butter and sugar. Beat on medium speed until the mixture is light and fluffy, about 3 to 5 minutes.
Stop the mixer and scrape down the sides of the bowl. Beat in eggs, one at a time, on low speed, beating for 1 minute between each addition.
Beat in the vanilla extract until well combined.
On low speed, add half of the dry ingredients. Stir on slow speed just to incorporate.
Add the orange mixture and sour cream and mix to just combine.
Add the final half of the dry ingredients. Stir on slow speed just to incorporate. Stop the mixer and scrape down the sides and the bottom of the bowl to find any hidden flour pockets. They’re in there!
Give the cake batter one last burst of energy, mixing on medium-high speed for about 30 seconds, just to get it all well incorporated.
Spoon half of the thick cake batter into the prepared pan and smooth the even. Add just over half of the crumble mixture and lightly swirl with a butterknife.
Add the remaining cake batter to the pan and smooth. Add the remaining crumble and again use the butterknife to swirl the cake batter over the crumble mixture – incorporating it.
Bake for 45 to 55 minutes, or until a skewer inserted into the cake comes out with moist crumbs, not wet batter.
Place on a wire rack to cool for 20 to 30 minutes. Before inverting the cake onto a wire rack, gently run a knife down the sides to help loosed any bits that may have stuck.
The key is to invert the cake while it’s just lightly warm, but not hot.
Slice and serve! You’re welcome to add a glaze. I like this cake served with lightly whipped cream and coffee.