1. Heat the oven to 350 degrees F. Line an 8 x 8 glass baking dish with aluminum foil.
2. In a small sauce pan, combine the olive oil and chocolate; cook over medium low heat, stirring frequently, until combined and smooth. Remove from heat and bring to room temperature.
3. In a large bowl, combine the eggs, sugar, cocoa, vanilla and salt; stir until combined. Add the cooled chocolate and mix well; add the flour and stir until no white streaks remain.
4. Transfer the batter to the baking dish and bake, about 25 minutes, or until a tester, inserted in the middle, comes out clean. Remove from the oven and cool completely before cutting.