Preheat the oven to 160ºC.

Line a slab tin (approx. 20cm x 30cm) using a sling method. That is make sure the baking paper extends over the sides of the sides of the slab tin by about 5 cm. I like to do this using 2 pieces of baking paper sitting over one another. First line the long edges and using a separate piece of baking paper, line the short edges/sides.

Using a stand mixer or hand mixer beat the butter, chocolate and the sugar until well combined and light and fluffy. 

Sift in the flour in 2 batches. Mix on a low speed between adding each batch of flour.

Press the thick dough into the lined baking tin, using a dessert spoon or offset spatula. You will think there’s not enough dough but it does eventually cover the bottom of the tin. It just needs a little coercing, poking and prodding. Securing the baking paper on the top edges with fold back clips or pegs, may help it from slipping about as you spread out the dough. Dipping the spoon or offset spatula frequently into water will help.

Place in the preheated oven for 25 minutes.

Once cooked remove from the oven and place the freckles in rows on top of the hot slice. Once you are happy with the placement of the freckles, press them firmly into the slice so that the slightly melted chocolate freckle sticks to the top of the cooked slice.

While the slice is still hot and still in the tin, using a sharp knife, cut the slice between the freckles to form squares or rectangles. It’s much easier to cut the slice while it’s hot, rather than when it’s cooled.

Allow it to completely cool in the tin.