- Preheat oven to 350 °F (180 °C). Grease and line a 9x13 inch (3.5L) baking pan with parchment paper.
- Place the chopped chocolate in a large bowl and pour boiling water overtop. Let the chocolate mixture sit one minute, then whisk to melt.
- Whisk in the sugar, then add the mayonnaise and then the eggs, one at a time. Stir in the vanilla.
- With a wooden spoon or spatula, stir in the flour, cocoa powder and salt until evenly blended. Stir in the chocolate chips.
- Scrape the batter into the prepared pan and spread evenly. Bake for about 30 minutes, until a tester inserted in the centre of the brownies comes out clean. Cool to room temperature.
- Brownies slice best when chilled, but taste best at room temperature. Once sliced, you can store the brownies in an airtight container for up to 5 days.
- You can use whole wheat flour in place of the all-purpose flour – the brownies will still be nice and dense.
- You can use dark chocolate, milk or white chocolate chips, but the dark adds the richest flavour.
- You can use regular or low-fat mayonnaise or homemade.
- The mayonnaise replaces the need for butter or oil (a typical brownie recipe this size would use a cup of butter!), and if you omit the chocolate chips, makes this recipe dairy-free, since unsweetened chocolate has no dairy in it.
- It doesn’t matter is you use regular or Dutch process cocoa powder.