‘brownie galette des rois’ with cocoa, coffee, chocolate, hazelnuts & chestnuts

cocoa puff pastry dough :

• cut up the butter in flat cubes, sprinkle with flour to avoid sticking, place on a plate and in the freezer for at least 30 minutes
• brew some strong espresso coffee, transfer to a cup, add 1 or 2 Ice cubes (total weight should be 125 ml/grams with the ice cubes) and place in the refrigerator
• combine the flour, cocoa powder, icing sugar and salt and chill in the refrigerator
• when everything is cold, place the dry ingredients in a large food-processor and pulse several times to combine, then add half the flat butter cubes and pulse 2 times for 1 second each time, then add the other half of the flat butter cubes and pulse again 2 times for 1 second, add half the chilled coffee and pulse 1 time for 1 second, then add the second half of the chilled coffee and pulse 2 times for 1 second each time
• scrape out the granular sandy mixture onto a work surface, form into a rough ball without kneading, wrap up in plastic film and refrigerate for at least 30 minutes
• remove the chilled dough from the refrigerator for 5-10 minutes before flattening and rolling out
• flour a work surface, shape the dough into a log, flatten out and roll it out into a very large rectangle (keep sprinkling with flour to avoid sticking on both sides), then fold over the sides (like an envelope), roll it up tightly and then roll it out again into a large 30 cm x 60 cm rectangle (about 3 mm thick)
• cut in half and shape each into a 30 cm x 30 cm square
• place each square sheet of dough onto a sheet of baking paper and use an empty tube to roll each one up into a cylinder shape and wrap in plastic film and let chill in the refrigerator until ready to use

chocolate-chestnut & hazelnut filling :

• beat the eggs in a large bowl using a mixer, then one-by-one, add and mix the chestnut spread, then the chocolate-chestnut spread and finally the ground hazelnut powder and mix until smooth, reserve in a bowl in the refrigerator until ready to use

flat chocolate squares :

• melt the dark chocolate in a double-boiler until smooth, spoon the mixture into square silicon molds (each of mine has 6 cavities measuring 4,5 cm x 4,5 cm each), let solidify at room temperature, then place in the freezer for easier removal and unmolding when ready to use)

assembly :

• remove the chilled dough from the refrigerator and place the first 30 cm x 30 cm square onto a baking sheet covered with baking paper, slice off 2,5 cm strips from each side, brush the edges with the egg and milk wash, place the strips on top of the edges and use them as borders to contain the filling, brush the tops of the dough strips with egg-milk wash too
• spread the filling inside the edges and borders, add a coin or ceramic figurine inside for the winner, brush the dough strip borders with egg-milk wash, place the second sheet of dough on top and trim all 4 edges for a neat and straight finish
• create a checkerboard design on top of the dough’s surface with a sharp knife, poke a few holes using a toothpick to release steam, brush the top of the dough with the remaining egg-milk wash
• place everything in the refrigerator for 1 hour minimum (or in the freezer for 20 minutes) while the oven preheats to 215°C
• bake at high heat for 10-12 minutes, then reduce the heat to 195°C and bake for an additional 20-25 minutes until puffy and dark-golden (it will be darker because the puff-pastry dough is darker)
• let the galette cool down almost (but not) completely before placing the flat chocolate squares on top (you can re-melt some chocolate and use it as a glue to secure the chocolate squares) until they very slightly melt and become shiny
• serve at room temperature or slightly chilled (it cannot be warmed up in an oven because the chocolate squares will melt) with a glass of cider.