In a food processor fitted with a metal blade, mix together chocolate chips, butter, brown sugar, cocoa powder and cinnamon. Process until blended but still somewhat chunky. Spread mixture on 4 of the bread slices. Top with remaining slices.

In a large bowl, whisk eggs. Add orange juice, milk, orange liqueur and vanilla. whisk well. Carefully dip each sandwich in egg mixture, turning to coat each side well.

In a large skillet over medium heat, melt butter. Carefully place dipped sandwiches in skillet and cook until browned and crisp on both sides, about 3 to 5 minutes. If sandwiches start to slide apart, gently press down on tops with spatula.

Serve French toast with warm maple syrup and fresh orange slices, if desired.

Tip:
If you are using a narrow loaf of bread, such as a baguette, just increase the number of French toast sandwiches per serving. Depending on the size of bread used, there will probably be some extra batter and filling. Do not use sourdough bread for this recipe.