Preheat the oven to 350°F. Spray an 8×8-inch glass baking dish with cooking spray.
Combine the beans, cocoa powder, espresso powder, and egg substitute in the bowl of a food processor. Process until the mixture is smooth, about 2 minutes, scraping down the bowl halfway through.
Add the chocolate syrup, sour cream, butter, Truvia, and vanilla. Process until all of the ingredients are combined, about 1 minute.
Pour the batter into the prepared baking dish, and smooth the top with a spatula. Bake for 28 to 30 minutes, turning the dish halfway through the baking time. A toothpick inserted in the center will come out with soft batter clinging to it.
Let the brownies cool completely in the baking dish on a wire rack. Then cut into 12 squares and serve. Refrigerate any leftovers.