Sliced one loaf of challah bread into 1-inch thick slices. In a large baking dish, combine eggs, cream, vanilla extract, sugar, cinnamon and 1/2 tablespoon instant coffee powder and whisk together. Lay bread in dish and let soak in the egg mixture for about 30 seconds each side.
Heat a skillet on medium heat and add 1 tablespoon of butter. Add french toast and fry until golden brown. Flip (adding more butter if needed, use your judgement) and fry on other side. Repeat with remaining slices of bread and tablespoons of butter.
Mix mascarpone cheese with honey and remaining coffee powder and spread on french toast slices while warm. Sprinkle with cocoa powder and serve with syrup and strawberries.