2 pounds apricots
2 to 4 tablespoons sugar, depending on the sweetness of the fruit
1 1/4 cups apricot jam, divided
1 1/2 cups boysenberries
1/4 cup sugar
1/2 teaspoon cinnamon
1. Cut the apricots in half and discard the pits. Put the apricots into a large bowl, add the sugar and stir to coat. Pour 1/2 cup of apricot jam over the top and stir again. The apricots should be lightly coated, with just a dab of jam sticking to the center of each.
2. In a separate bowl, gently stir 1/4 cup of jam with the boysenberries, being mindful to keep the berries whole.
3. To shape the dough, divide it in half. Keep half chilled while the other half is being shaped. Flour the work surface and roll the dough into a rough circle about 15 inches in diameter. Transfer the circle of dough to a baking sheet lined with parchment.
4. To form the tart, smear 1/4 cup of jam at the bottom of the tart. Pile half of the apricots and half of the boysenberries into the center of the dough, tucking the boysenberries into the nooks and crannies of the apricots. Fold an edge of the dough toward the center to cover the fruit; about 3 inches of crust should be showing. Continue folding the edge of the dough toward the filling and over to create folds. Each one will look different.
5. Once the tart is formed, it should be about 9 inches in diameter. Using the same procedure, shape the second tart on a separate parchment-lined baking sheet. Freeze both tarts for a minimum of 1 hour.
6. While the tarts are freezing, heat the oven to 350 degrees.
7. Stir the sugar and cinnamon together. Whisk the egg to make an egg wash. Take the baking sheets out of the freezer and brush the edges of the dough with the egg wash. Sprinkle half of the cinnamon sugar evenly over each of the tarts, on both the crust and the fruit. Don't skimp — it creates a great crust.
8. Bake, rotating the pans halfway through, until the crusts are dark golden brown and blistering, the jam is bubbling and perhaps some juice has run from the tart and caramelized on the parchment paper, about 60 to 70 minutes.
9. Serve the tarts warm from the oven or later that day. The unbaked tarts will keep, well wrapped and frozen, up to 1 month.
Each serving: 333 calories; 4 grams protein; 54 grams carbohydrates; 3 grams fiber; 13 grams fat; 7 grams saturated fat; 48 mg. cholesterol; 30 grams sugar; 115 mg. sodium.