Preheat oven to 400F. Line a large, rimmed cookie sheet with parchment.

Lay the Saltine crackers down in a single layer on the parchment paper.

Put the brown sugar and the butter in a small saucepan. Melt the butter and bring to a good boil. Boil for 3 minutes without stirring.

Pour the mixture over the crackers. Put in oven for 5 minutes.

Remove from oven and dollop spoonfuls of peanut butter over the crackers. Return to oven for 1 minute. Remove and spread the peanut butter all over the crackers. Top with the semisweet chocolate chips and return to oven for 1 minute. Remove and use a spatula to spread the chocolate all over the top. Top with the chopped M&Ms.

Let set completely (I let mine sit overnight) before breaking apart.