¼cup/60 milliliters buttermilksour cream or whole milk yogurt
1cupmixed berriessuch as strawberries, blueberries or raspberries, more as needed
1tablespoonturbinadoor use granulated sugar
Confectioners’ sugarfor serving
Whipped cream or crème fraîcheoptional
Heat oven to 375 degrees and butter a 10-inch tart pan with a removable bottom. Line the bottom with a round of parchment, and butter that as well.
In a large bowl, whisk together almond, all-purpose, whole wheat and buckwheat flours, baking powder and salt.
Using an electric mixer, beat together butter, sugar and vanilla extract until pale and fluffy, about 3 minutes. Beat in egg, scraping down sides of bowl as necessary. Beat in buttermilk. (The mixture will look curdled, and that’s O.K.) Stir in flour mixture until just combined.
Scrape batter into prepared pan, smoothing and leveling the top. Place berries on top of batter and sprinkle with turbinado or granulated sugar.
Bake until golden and a toothpick inserted in the center comes out clean, 25 to 30 minutes. Cool to room temperature on a wire rack and unmold. Sprinkle with confectioners’ sugar and serve, with whipped cream if you like.
We used sour cream, in lieu of buttermilk. The resulting flavor and texture was sublime.