Caramelized Croissant French Toast

Name: Caramelized Croissant French Toast
Ingredients: 8 tablespoons (3 1/2oz/ 99g) granulated sugar (divided); 4 tablespoons (2oz/ 56.7g) unsalted butter; Fresh berries, whipped cream or ice cream for serving (optional); 4 large croissants or 6 medium (white bread such as hearty sandwich bread, challah or brioche cut into 1-inch thick slices may be substituted *see note); 2 eggs; 1/4 cup plus 2 tablespoons (3oz/ 85g) milk; 2 tablespoons (0.8oz/ 23g) heavy cream; 2 tablespoons (1/2oz/ 14g) all-purpose flour; 1 1/2 teaspoons (1/4oz/ 7g) granulated sugar; 1 teaspoons pure vanilla extract or 2 teaspoon if using imitation vanilla flavoring; 1/2 tsp ground cinnamon