Preheat oven to 350F. Line an 8-inch square baking pan with a lightly floured piece of parchment paper.
Melt chocolate on the stove-top or in the microwave in a double boiler and whisk in the Olive Oil. Let cool.
Mix the flour and salt together in a small bowl. In a large bowl, beat the eggs and sugar until pale, thickened and billowy- about five minutes. Fold in the vanilla and the cooled chocolate mixture, then fold in the flour and nuts, stirring just until everything is combined. Pour into the prepared pan.
Bake for 22-26 minutes. Cool completely, then cut into squares