Preheat the oven to 350°F and line a 9×13-inch pan with parchment paper.
In a large bowl, whisk together the melted coconut oil, coconut sugar, and maple syrup until smooth. Add the eggs, egg yolk, molasses, and vanilla extract and whisk until fully combined.
In a separate bowl, whisk together the all purpose flour, oat flour, ground ginger, cinnamon, baking powder, and salt. Add the dry ingredients to the wet ingredients and fold gently just until combined.
Spread the batter evenly into the prepared pan. Bake for 22 to 24 minutes, until the edges are set and the center is just slightly soft.
Let the brownies cool completely in the pan.
To make the frosting, beat the softened cream cheese until smooth. Add the Greek yogurt, maple syrup, vanilla extract, gingerbread spice, and salt. Beat until thick and creamy.
Spread the frosting over the cooled brownies. Chill for 20 minutes before slicing.
