Lay half of the bread slices out on a clean bench. Sprinkle chocolate evenly over each slice then top with remaining bread. Squash each together slightly to sandwich.
In a large shallow dish, add vodka, cinnamon, cocoa, eggs and cream and whisk well to combine.
In a large frying pan over medium heat, melt a third of the butter. Using tongs, dip sandwich in vodka/egg mix and add to pan. Cook until golden then flip and cook other side. When both sides are golden, remove from pan and set aside (keep warm). Repeat with remaining butter and sandwiches.
Serve with mascarpone, berries and mint.