Add all wet ingredients ( oil, milk, vanilla extract, brown sugar, white sugar ) to a mixing bowl and whisk to combine.
Add dry ingredients ( oat flour, salt, baking soda ) to wet ingredients and fold with a spatula till well combined.
Now add chocolate chips, pecans to the dough and fold in. Refrigerate dough for 15 mins.
Take a scoop of cookie dough onto your palm and press lightly to make a disc, place a vegan marshmallow in the center and cover with the dough. Repeat till cookie dough is complete.
Place marshmallow stuffed cookie scoop on a parchment-lined baking tray, leaving a gap in between each scoop, and bake at 350F for 6 mins.
Remove the baking tray from the oven, top each cookie with more chocolate chips and marshmallows, and bake for another 2 mins.
Let cookies cool on the cooling rack before serving!