Preheat the oven to 350 degrees F.
Line two muffin tins with festive cupcake liners. NOTE: this is an optional step - be sure to use good quality liners or spray with cooking spray to prevent the mixture from sticking to the liners. If you have a silicone muffin tin or liners - that's a great option as some bakers have found the paper liners to stick!
Place a Ritz cracker in the bottom of each liner.
In a medium sauce pan melt butter over medium heat, add brown sugar and bring to a boil. Boil for 2-3 minutes, allowing the mixture to bubble and caramelize.
Remove from heat and drop a tablespoon size amount of the mixture onto each ritz - use a cookie scoop.
Place in the oven and bake for 8 minutes.
Remove from the oven and immediately top each Ritz with 1 - 2 Tbsp chocolate chips.
Once they melt a little, spread the chocolate with the back of a spoon. Tip: if the chocolate chips are not melting, put the tray back in the warm oven for a minute to help them melt.
Top with festive sprinkles.
Place in the fridge to cool and set.
Store in an airtight container on the counter for a few weeks, these also freeze well.