1 Preheat the oven to 190 degrees or 170 degrees if using a fan oven. Lightly grease and line a 20 x 20cm sq baking tin with parchment paper, ensuring there is a few centimetres of paper hanging over the sides; this will make removing the blondies much easier when baked.

2 Put the butter into a small saucepan over a low heat and melt gently. Alternatively, melt the butter in the microwave. Set aside to cool slightly.

3 Pour in the cooled melted butter into a large bowl and add the peanut butter. Whisk well until smooth. Add the brown sugar and whisk well until combined.

4 Add the egg, followed by the vanilla, and whisk again until well mixed.

5 In a separate bowl, sift in the flour, baking powder and salt, and then gently fold the dry ingredients into the butter, sugar and egg mix, taking care not to overmix.

6 Add the chopped chocolate, chopped peanuts and the tablespoon of milk and fold through until just evenly dispersed.

7 Pour the batter into the prepared tin and smooth the top using the back of a spoon or spatula.

8 Arrange the pretzels on top of the batter, pushing the pretzels ever so slightly into the mix. The batter will cook up around the pretzels but they will stay visible.

9 Bake the blondies in the preheated oven for 25-30 minutes, until golden. Check they are cooked by sticking a skewer or sharp knife into the centre; it should come out clean.

10 Remove the blondies from the oven and leave to cool for 10 minutes in the tin before removing from the tin, placing on a wire rack, and leaving to cool completely.

11 Cut into nine squares and sprinkle with a little sea salt.