How to Make It
In a medium bowl, cover the dates with water and let soak for 2 hours; drain. Pit the dates.
Line a baking sheet with parchment paper. In a food processor, pulse the hazelnuts until coarsely chopped. Add the dates, almond flour, a pinch of salt and 6 tablespoons of the coconut oil and pulse until the dough just comes together. Turn the dough out onto the prepared baking sheet. Top with a sheet of parchment paper and press the dough into a 10-inch round, about 1/4 inch thick. Freeze the crust until firm, at least 1 hour.
Meanwhile, in a medium saucepan, bring the coconut cream and agar to a simmer, whisking to dissolve the agar. Remove from the heat and whisk in the 1/4 cup of confectioners’ sugar and the remaining 2 tablespoons of coconut oil. Scrape into a large bowl, cover and refrigerate until chilled and firm, at least 1 hour.
Carefully transfer the tart shell to a platter and peel off the top sheet of parchment paper. Using a hand mixer, beat the coconut cream mixture at high speed until smooth and fluffy, about 5 minutes. Spread it all over the tart shell, leaving a 1/4-inch border, and top with the berries. Loosely cover the tart and refrigerate for 30 minutes. Dust with confectioners’ sugar and garnish with microbasil, if desired. Serve cold.
Coconut cream and agar, a natural thickener, are available at Whole Foods and on amazon.com.