Preheat oven to 350°F (175°C) and grease a 9x9 inch square baking pan or line with parchment paper.
In a large mixing bowl, whisk together the rolled oats, flour, brown sugar, baking soda, and salt.
Add 1 cup of melted vegan butter and vanilla extract to the dry ingredients, stirring until a uniform crumbly dough forms.
Press two-thirds of the oat mixture firmly into the bottom of the prepared baking pan to form the base crust.
In a heavy-bottomed saucepan over low heat, combine the vegan chocolate chips, condensed coconut milk, 2 tablespoons of vegan butter, and sea salt.
Stir the chocolate mixture constantly until melted and smooth, then pour it evenly over the oat base.
Crumble the remaining oat mixture over the chocolate layer, pressing down slightly.
Bake for 25 to 30 minutes until the edges are lightly browned.
Remove from oven and cool completely in the pan on a wire rack.
Refrigerate for at least 2 hours to set the fudge layer before slicing into 16 bars.