2. Using a blender, food processor or coffee grinder, blend half of M&Ms into candy bits and dust. Set aside.
3. In a large skillet over medium heat, start by cooking the bacon. Cook until crispy, flipping slices in between.
4. While bacon is cooking, microwave popcorn packages separately. Once popped, open bags and gently pour popcorn into a roasting pan. *Note: Shake the bags before opening to encourage the leftover kernels to fall to the bottom, then pour slowly to avoid dumping them all into a roasting rack.
5. Once the bacon is crispy, use fork or tongs to remove slices from pan. Use a clean kitchen towel (or paper towel) to absorb the extra fat. Chop bacon into fine pieces and set aside.
6. Add butter to bacon fat and melt. Once melted, add brown sugar and stir until combined. *Note: Do not use any metal utensils during the caramelization process. Keeping the heat on medium, allow the bacon fat, butter, and sugar to cook for several minutes. You’ll start to see all of the ingredients rolling into one another, starting in the middle and working out towards the edge of the skillet. During this time, do not stir or touch the sugar.
7. Once the caramel has reached the outer edge, add the vanilla extract. Using a non-metal utensil, stir the mixture gently.
8. Finally, add the baking soda and cream of tartar. Mix well.
*Note: The entire process of making the caramel sauce should only take about 5 minutes. Pay close attention to how your sugar is responding in the pan to avoid burning.
9. The sauce is now ready to be poured over the popcorn.