Mary Berry’s Chocolate Brownie Mix with Caley Brothers Oyster Mushroom Powder

Chocolate Brownie

Mary Berry's Chocolate Brownie Mix with Caley Brothers Oyster Mushroom Powder
Course: Dessert, Snack
Cuisine: American


  • 275 g (1 1/4 cups)  softened butter
  • 375 g (1 7/8 cups) caster sugar
  • 4  large eggs
  • 75 g (5/8 cups) cocoa powder
  • 100 g (3/4 cups)  self raising flour
  • 100 g (2/3 cups) dark chocolate chips
  • 30g  finely blended fried oyster mushrooms
  • 30ml of tepid water


  • Preheat the oven to 180°C/Fan 160°C/gas 4.
  • Line the base and sides of a 30cm x 23cm x 4cm traybake or roasting tin with baking paper. Grease the tin and then line it with the paper.
  • Measure all the ingredients into a large bowl and mix with a hand-held electric mixer until evenly blended.
  • Spoon the mixture into the prepared tin, scraping the sides of the bowl with a plastic spatula to remove all of it. Spread the mixture gently to the corners of the tin and level the surface with the back of the spatula.
  • Bake for 40–45 minutes, until the brownies have a crusty top and a skewer inserted into the centre comes out clean. Cover loosely with foil for the last 10 minutes if the mixture is browning too much.
  • Allow the brownies to cool in the tin and then cut into 24 squares. 

Brownies will store in a cool place for up to 5 days in an airtight container.