Tip the yeast sachet into a bowl and pour over the 400ml of lukewarm water. Let stand for 2 minutes. Place the bread mix and the sugar into your electric mixer bowl with a dough hook and add a tablespoon of olive oil and the yeast mix. Mix for 1 minute on a low speed, scrape down sides and mix for another 3 minutes on medium to high.
Add chocolate chips and mix on medium speed for another minute. Scrape down the sides and make sure all the flour is incorporated. The mixture will be quite wet but that is fine. Place the bowl in a warm, draught-free place (near a preheating oven) with a tea towel on top. It might be warm enough to just leave on the bench. Allow to rest for 5 minutes.
Dust the bench top with gluten free flour, tip mixture on to the bench and, using a sharp knife or pastry cutter, cut into 10 equal sized pieces. Flour your hands and roll each piece into a ball.
Place on a baking sheet lined with baking paper. Place about 2cm apart. Cover with a damp tea towel and place in a warm place until they almost double in size (about 30 to 40 minutes). About 10 to 15 minutes before they have finished rising, preheat the oven to 200ºC.
Make the cross mixture by mixing the gluten-free flour and cocoa together, then add the water and whisk to make a smooth paste. Pour cross mixture into a snaplock bag or piping bag. When the buns have risen to twice their size, cut the corner from the snaplock bag and pipe cross mixture onto the buns.
Place buns in the oven, and put a second baking tray below the buns with 2 ice cubes to create some steam in the oven. Bake buns for 20 to 25 minutes or until golden. Remove from the oven. Combine apricot jam and water and heat in the microwave or on the stove for about 20 seconds to make the glaze. While buns are still warm, brush the glaze onto the tops of the buns with a pastry brush. Serve warm with butter.