Preheat the oven at 350 degrees Fahrenheit (180 degrees Celsius)

In a bowl blend the olive oil and sugar well with a large spoon until smooth. Add vanilla and mix well.

Beat the eggs in a small bowl and add to the olive oil mixture and mix well.

Add the yogurt and mix well.

In another bowl blend the flour, cocoa powder, salt and baking powder. Add to olive oil mixture and mix well.

Incorporate the nuts and mix again.

Line a 9 inch square pan (22 cm) with wax paper and carefully pour the brownie mixture in the pan, smooth the top with a spatula.

Bake for about 25 minutes.

Let it cool completely, remove the wax paper and cut in squares.