Like oreo cookies but better! These cookies don't use butter. You can easily use gluten-free flour too.

Makes 12-14 sandwiched cookies
1/2 c/90g dark chocolate or chocolate chips
40ml hot water
1 c flour (I used spelt)
1 tsp baking powder
1/4 c icing sugar
1 egg 

Peppermint filling:
1 c icing sugar
1 tsp peppermint extract
1-2 tbsp water

Melt the chocolate and hot water in a double boiler or in a microwave. Stir until smooth and let cool.
In a medium bowl sift the flour, sugar and baking powder. Mix the egg with the chocolate mixture then pour over the flour and stir to combine. Use your hands to scoop into a ball and mix in all the crumbly bits. Wrap in cling film and refrigerate for 15 min.
Preheat the oven to 180C and line a baking sheet with baking paper.
Roll out the dough between 2 pieces of baking paper to 3mm thick. Cut into your desired shapes (around 5cm wide) and place onto your baking tray. Repeat until all the dough is used. Circles are easy and work well. I have a cool cutter cube with the playing card suit shapes on it.The cookies don't spread so you can place them close together. Bake for 10 min.
Let cool on a wire rack.
In a small bowl mix the icing sugar and peppermint extract together with enough water to make a spreadable paste. Spread a little filling onto one cookie and sandwich another one on top.
Mint is a universal favourite but you could experiment with other flavoured fillings, such as orange or berry, which also go well with chocolate.