Step 1

Preheat the oven to 180C/350F and line two baking sheets with parchment paper.

Step 2

Cream the sugar and butter in a bowl with an electric mixer until it is creamy and soft.

Step 3

Mix the arrowroot and water in a cup and then add to the bowl along with the vanilla essence and stir.

Step 4

Sift the baking powder and flour into the bowl, and fold. Then sift in the cocoa powder and stir. You may find it easier to use your hands to mix.

Step 5

If you are using chocolate bars, cut into chocolate chip sized chunks and add. Stir so they are evenly distributed.

Step 6

Using your hands, divide the mixture in half, and then half again so that you have 4 equal parts. Then divide each part into 4 golf sized balls. You should make 16 in total.

Step 7

Place them onto the baking paper making sure to leave enough room for each to spread. Gently push them down.

Step 8

Place 1/2 tsp of peanut butter on top of each cookie and with a cocktail stick gently swirl into the cookie.

Step 9

Place in the oven for 10-12 minutes. They may still look soft and gooey in the middle but don't be tempted to leave them in longer. They will set when cooling and give that perfect gooey texture inside.

Step 10

Sprinkle each cookie with some sea salt.

Step 11

For best results eat on the same day but they will keep for 2-3 days in an airtight container.