Directions

1. Preheat your oven to 356 degrees. Prepare an 8" square baking pan by lining with parchment paper, and then greasing with cooking spray.
   
2. Put the butter into a large bowl and melt in the microwave in 10 increments. Continue until the butter is partially melted but not hot. Then stir to melt the rest.
   
3. Add the coffee and brown sugar to bowl and stir it in. Mix in the egg and vanilla.
   
4. Fold in the flour, baking powder, and salt. Mix until you have a thick glossy batter. Pour the batter into the prepared baking pan. Give it a gentle shake to level it out.
   
5. Bake for 25–28 minutes, until the blondies are set at the edges (which will have risen and become slightly wrinkled). There will be a shiny papery crust on top. The middle should be soft and still slightly wobbly.
   
6. Place the pan on a wire rack and allow to cool for 10–15 minutes to firm up. The centre will continue to cook in the residual heat. Then gently lift out of the pan and cut into 16 squares.