Preheat the oven to 350°F and line a 9×9-inch pan with parchment paper.
In a small bowl, melt the bittersweet chocolate, olive oil, and red food gel over a saucepan of simmering water, stirring until smooth. Remove from heat and allow to cool slightly.
Meanwhile, in a large bowl, beat the sugars, eggs, vanilla, and white vinegar on high speed for about 5–6 minutes, until the mixture has doubled in size. Scrape down the bowl to ensure everything is fully combined.
Reduce the mixer speed and slowly pour in the chocolate mixture.
Add the flour, cocoa powders, and salt, folding gently until mostly combined.
Fold in the chopped chocolate until evenly dispersed.
Pour the batter into the prepared pan and smooth the top with an offset spatula.
Bake for about 35 minutes.
Allow the brownies to cool completely in the pan before removing.
Cut into 16 squares, top with flaky sea salt if desired, and enjoy.