Preheat the oven to 350°F / 180°C.
Add the firm tofu, rolled oats, soy milk, softened dates, cacao powder, ground chia or flax, baking powder, vanilla, salt, maple syrup, and coffee to a blender.
Blend until grainy smooth (or fully smooth if you prefer a smooth texture), stopping to scrape down the sides as needed.
The mixture should resemble thick brownie batter. If it is too thick to blend or pour, add additional soy milk a little at a time.
Pour the batter into a lined or lightly greased 8 x 8-inch / 20 x 20 cm baking dish.
Sprinkle the chocolate chips over the top, and smooth the surface to make sure the chocolate chips are roughly evenly spread out over the top..
Bake for 30 to 38 minutes, until the top and edges are set.
Let cool for at least 15-20 minutes before slicing (depending on your home temperature, this could take longer). The baked oats will firm further as they cool.
If making the frosting, stir together the thick soy yogurt, cacao powder, and sweetener until smooth. Spread over the baked oats once they have cooled.