- 1 stick (1/2 cup) cold unsalted butter
- 1/4 cup plus 1/3 cup sugar
- 1 cup flour
- 1/2 teaspoon salt
- 1/3 cup blanched whole almonds
- 1 teaspoon unflavored gelatin
- 1 tablespoon cold water
- 1/2 cup heavy cream
- 3 tablespoons sugar
- 1/8 teaspoon salt
- 1 cup low-fat buttermilk
- 1 tablespoon fresh lemon juice
- 4 containers (17.6 oz) fresh blueberries
- 1 container (4.4 oz) fresh raspberries
With the paddle attachment of an electric mixer on low speed, beat butter and 1/4 cup sugar until just combined, about 15 seconds. Add flour, almond/sugar mixture, and salt and beat until the dough comes together, about 3 minutes.
Press dough evenly into a 12-inch round tart pan with removable bottom, using the bottom of a glass to ensure evenness if necessary. Refrigerate until firm, at least 30 minutes (up to 1 day).
Preheat oven to 325 degrees Fahrenheit. Bake tart shell, occasionally pressing the bottom to flatten using a glass (I did this 3 times), until golden brown, about 30 minutes. Let cool.
Sprinkle gelatin over the water in a small bowl and let stand until softened, about 5 minutes.
Heat cream, sugar, and salt in a small saucepan over medium heat, stirring to dissolve sugar and salt. Add gelatin mixture and stir until fully dissolved. Remove from heat; let cool. Stir in buttermilk and lemon juice.
Remove tart from pan. Spread filling into crust. Refrigerate until filling is slightly set, about 15-20 minutes. Scatter berries evenly over top. Refrigerate unti lfilling is firm, about 2 hours (up to 1 day). Cut and serve.
Serves 8 to 12, depending on how generously you cut your wedges.