Preheat oven to 350°F.
Spray an 8x8 pan with non-stick cooking spray.
In a stand mixer with paddle attachment, combine butter and brown sugar until creamy and add vanilla until fully incorporated.
Add in ¼ c M&M’S® Minis Chocolate Candies, oatmeal, raisins, cashews, baking soda, flour and salt until fully combined.
Press ¾ of the dough into the bottom of prepared pan. Bake for approximately 10-13 minutes. Center will still be partially uncooked.
While the bars are baking, prepare caramel sauce in a saucepan over low heat by melting the caramels, butter and heavy cream.
Pour the hot caramel sauce over top of the par-baked dough.
Top with the rest of the M&M'S® Minis Chocolate Candies. Crumble the remaining dough over top and bake for another 10 minutes.
Remove and cool for approximately 15 minutes.
Cut into 20 equal portions.
Serve bars individually wrapped.