Flourless Black Bean Brownies

black beans, drained and rinsed well

eggs (100 g, weighed out of shell), at room temperature

neutral oil (like grapeseed, canola or vegetable)

pure vanilla extract

strong brewed coffee (can use decaf)

unsweetened cocoa powder (natural or Dutch-processed, your choice)

baking soda

kosher salt

packed light brown sugar

semi-sweet or dark chocolate chips (optional)