Preheat oven to 350°F (175°C). Lightly grease a 9” tart pan or pie dish.
Mix almond flour, oat flour, melted coconut oil, maple syrup, vanilla, and salt in a medium bowl until combined. Press evenly into the bottom and up the sides of your tart pan.
Bake for 20–25 minutes or until golden brown. Let cool completely before filling.
Wash and pat dry all the berries. Arrange them in the cooled crust, starting with the larger ones and filling in with smaller ones.
Whisk together juice, lemon juice, maple syrup, and arrowroot in a small saucepan over medium heat. Stir continuously until thickened and glossy, about 3–5 minutes. Remove from heat and let cool slightly.
Spoon the glaze evenly over the berries. Let the tart chill in the refrigerator for at least 30 minutes before slicing.
Serve and enjoy! Garnish with mint leaves or a dusting of coconut sugar if desired.