Preheat the oven to 350 degrees Fahrenheit and line a rimmed sheet pan with parchment paper.
Spread the flour onto the sheet pan and bake in the oven for 5 minutes or until the flour reaches 160 degrees F.
Using a mixer, beat the salted butter, brown sugar, and granulated white sugar until combined, or 2-3 minutes. Beat in the peanut butter, caramel syrup, vanilla extract, and salt. It should take 1-2 minutes to mix them completely.
Add the all-purpose flour into the mixer.
Start the mixer on the lowest speed so the flour doesn’t spill out and gradually increase the speed. Beat until combined, about 1-2 minutes.
Fold in the old-fashioned oats, semi-sweet chocolate chips, and ¾ cup of mini M&Ms.
Pour the dough into the baking pan and press to form to the bottom of the pan.
For the chocolate topping, microwave the semi-sweet chocolate chips and half and half together in a microwavable bowl. Microwave in increments of 15 seconds, stirring between each session to make sure it doesn’t burn. It should take about 4-6 increments of 15 seconds until it is completely melted and mixed.
Pour the chocolate topping over the dough in the baking pan so that it spreads over the whole area. Spread with a knife if necessary. This is much easier done when it’s still warm. Sprinkle with remaining ¾ cup mini M&Ms.
Chill in the refrigerator for 1-2 hours or until completely set. Cut into bars and then enjoy.
Storage:Store these bars in an airtight container in the refrigerator for up to 2 weeks. When ready to serve, set out to warm to room temperature and enjoy. These are also great to freeze for up to 3 months.Tips:To melt the chocolate topping, you can simply microwave the mixture. I’ve found it works best to microwave in increments of 15 seconds, stirring between each session to make sure it doesn’t burn. It should take about 4-6 increments of 15 seconds until it is completely melted and mixed. Spread it over the dough immediately, as it’s much easier when it’s warm.Inspired by Dinner at the Zoo