Preheat the oven to 180°C.
Grease an 18cm square cake tin and line it with baking parchment.
Cream the butter and sugar in a bowl until fluffy, then beat in the eggs individually.
Chop the chocolate into small pieces.
Fold the chopped pecans, chocolate, and vanilla extract into the mixture.
Dissolve the coffee granules in 2 tbsp of warm water and stir into the batter.
Add baking powder, then sift in the flour and cocoa powder before mixing well.
Spoon the batter into the tin and level it with a spatula.
Bake for 35 to 40 minutes and cool in the tin before transferring to a rack.
Cut the brownies into rectangles and dust them with icing sugar.