Make the french toast: In a shallow bowl, whisk eggs, milk, molasses, and spices until smooth.
Heat a skillet over medium-high then add butter until melted and hot. Working in batches, dip french bread slices in egg mixture and place in hot skillet. Cook 1-1/2 to 2 minutes on each side, flipping once. Keep french toast warm.
Make the walnut caramel sauce: In a small pan over medium-high heat, bring butter, sugar, agave, and water to a low simmer. Cook caramel until a dark golden brown. Remove from heat and whisk in cream and salt. Stir in walnuts and serve caramel sauce warm over french toast. Enjoy!