Line 1 large or 2 small jelly-roll pans with aluminum foil, spray with nonstick spray and arrange the Ritz salt-side down in a single layer. In a medium saucepan, melt the butter or margarine and brown sugar together, add the corn syrup and vanilla, and boil until it turns a caramel color. Remove from the heat and pour over the crackers, covering them evenly.
Put the jelly-roll pan into the oven and bake for 3 to 5 minutes, or until just bubbly, watching carefully. Remove from the oven and pour the chocolate chips over the crackers. When the chips melt a bit, spread them over the crackers with a knife.
Transfer the pan to the freezer for 15 to 20 minutes, or until completely cold. They will form one big sheet. Break up into pieces. Store in an airtight container
Recipe by Dang Good Cookin' at https://danggoodcooking.com/sweet-ritz-bark/