Vegan Chocolate Tart with Salted Oat Crust

Name: Vegan Chocolate Tart with Salted Oat Crust
Cuisine: European, Mediterranean
Ingredients: 1¼ cups old-fashioned oats; ¾ cup whole wheat flour; ⅓ cup virgin coconut oil, melted, slightly cooled; ¼ cup light agave syrup (nectar); 2 tablespoons unsweetened cocoa powder; ¾ teaspoon kosher salt; ½ teaspoon ground cinnamon; ½ teaspoon instant espresso powder; 1 cup unsweetened cocoa powder; 7 ounces vegan dark chocolate, melted, slightly cooled; ⅔ cup light agave syrup (nectar); 2 teaspoons vanilla extract; ⅔ cup plus 1 teaspoon virgin coconut oil, melted, slightly cooled; ¼ teaspoon kosher salt, plus more; 2 tablespoons old-fashioned oats; 1 tablespoon demerara sugar; Flaky sea salt; A 9-inch-diameter or a 13¾x4½-inch tart pan with removable bottom