Directions

1. Melt the butter and chocolate together in a medium sized bowl in the microwave. Start with 1 minute and then decrease to 30 seconds intervals until the mixture is melted.
   
2. In the bowl of an electric mixer with whisk attachment add the eggs and caster sugar. Turn it on low and whisk until smooth. Add the chocolate and butter mixture into the eggs, whisk on low until combined.
   
3. Now turn the machine on medium and beat the eggs and chocolate until doubled in volume and paler in color. Preheat the oven to 360°F.
   
4. Add the flour, cocoa powder, baking powder and salt, mix until just combined. Take the bowl out of the mixer and fold in the walnuts (optional).
   
5. Spray a 8 x 8 inches pan with nonstick spray and pour the mixture into the pan and even out the top. Bake for 25-30 minutes. A toothpick inserted should come out with a few gooey crumbs.
   
6. Place on a wire rack and sprinkle with flaky salt. Wait until the brownies are cool then cut into squares. Enjoy!