Add flour, hard cold coconut oil or (vegan) butter, coconut sugar, salt and (optionally) cinnamon to the chilled bowl of a food processor and pulse to combine (pulse 8-10 times to get small floury flakes).
Slowly pour ice water into the blender bowl while it is running until the dough comes together.
Turn the dough onto a lightly floured surface and pat it down into a disk shape about 1 inch/2.5cm thick, wrap it in cling foil and refrigerate it for about 30 minutes.
Preheat oven to 350F/175C
While the dough is chilling, combine the raspberries, 2 tsp of coconut sugar and arrowroot in a bowl and gently toss to combine.
Roll out the galette dough between 2 pieces of parchment into a 12" /30cm circle.
Take of the top piece of parchment paper and add the berry mixture to the center of the dough, leaving about a 2-inch/ 5cm border all the way around.
Fold up the edges of the crust by taking a section of the edge of the dough and folding it up over the berries. Repeat until all of the edge has been folded around the berries.
Optionally brush some water or plant based milk over the exposed edges of the dough and sprinkle it with 1-1½ tsp of coconut sugar.
Bake the galette for 35-40 minutes, until the edges are golden brown.
Take the galette out of the oven and allow it to partially cool before slicing.