To make the sauce, melt butter in a saucier or small saucepan. We used our All-Clad TK Saucier. Once the butter is melted, add the brown sugar and bring to a simmer until the sugar is incorporated. Add mashed banana and Kahlúa, and simmer for about 10 minuets. Remove from heat and serve.
To make the French toast, blend the eggs, milk, and vanilla until smooth. Put the mixture in a shallow dish and cut diagonal slices of Challah into 1.5” slices. Melt a few tablespoons of butter over medium heat in a large skillet or on a griddle.
Dip each slice of bread in the batter mixture and coat well on each side. Place each slice in the hot pan or on the hot griddle and cook for 3-4 minutes per side, until the bread is toasted and the egg is fully cooked. Serve immediately drizzled with banana Kahlúa syrup and top with sliced bananas.