In a food processor, combine rolled oats, cocoa powder, maple syrup, melted coconut oil, and a pinch of salt. Blend until the mixture resembles coarse crumbs, then continues until a dough forms, about 1–2 minutes. Press this dough firmly into the bottom and sides of a tart pan.

Using the same food processor, add canned coconut milk, more maple syrup, cocoa powder, melted coconut oil, and vanilla extract. Blend until the filling is smooth and creamy, which should take about 1–2 minutes. Adjust sweetness if needed.

Pour the creamy chocolate filling into the crust, spreading it evenly with a spatula. Place the tart in the refrigerator to chill for at least one hour, or until set.

Before serving, top with fresh berries and gently press them into the filling for a beautiful presentation.