Preheat the oven to 350°F/180°C/Gas Mark 4

Spray an 8-inch square pan with olive oil. Set aside.

Place the honey in a large glass measuring cup. Microwave on high power until the honey is runny and just bubbling, 45 to 60 seconds. Add the cocoa and stir with a fork until well combined. Let cool to room temperature (15 minutes).

Meanwhile, in a small bowl, place the flour, baking powder, baking soda, and salt. Whisk until well combined.

In a large bowl, combine the applesauce, egg, and vanilla. Whisk together until well blended. Add the honey-cocoa mixture and whisk until smooth. Add the flour mixture to the liquid mixture and stir until no traces of flour remain. For some texture you can add some mini chocolate chips and chopped walnuts. Scrape the batter into the prepared pan.

Bake until the surface looks dry around the edges of the pan and a toothpick inserted in the center comes out with moist crumbs clinging to it, about 25 minutes. Do not overbake.

Place the pan on a cooling rack and let cool completely before slicing into 16 squares.