Preheat oven to 180celsius. Grease a 8x8 tart pan. Set aside.
In a bowl, combine oat flour, hazelnut flour, coconut oil, vanilla and maple syrup. You should get a moist mixture than can be easily moulded. Firmly press into bottom and up the sides of tart tin. Bake for 20-25mins until crust is golden brown. Transfer to a wire rack and let it cool.
Pour the coconut cream, soy milk, maple syrup, cornstarch and vanilla bean paste into a medium pan. Place pan on the stove on low heat. When the mixture becomes warm, add the agar-agar. Stirring constantly, cook until agar completely dissolve. Allow to boil for approximately 30 to 60 seconds.
Pour mixture into tart and refrigerate at least 4 hours or overnight to set. Top with fresh berries and serve.