Preheat the oven to 350 degrees F. Spread the pecan pieces out on a rimmed baking sheet. Bake for 5-8 minutes to toast. Then set aside to cool.
Meanwhile, place the oil in a large heavy-bottomed sauce pot. Add the popcorn kernels and set over medium heat. Cover the pot, but open the vent to let the steam out. Pop the corn. The moment the kernels start to slow down, remove from heat and pour the popcorn out of the pot and remove any unpopped kernels. (You can pour it in a large bowl or on the baking sheet with the pecans.)
Wipe the pot out with a paper towel, then place back over medium heat. Add the butter, sugar, marshmallows, salt and cinnamon. Stir continuously until the marshmallows are completely melted and the sugar crystals have dissolved. Turn the heat off and pour the popcorn and pecans into the pot over the marshmallow mixture.
Using a large wooden spoon, mix the popcorn until completely coated. Make sure there is not a pool of marshmallow down at the bottom of the pot. After it is well mixed (and has cooled a little) sprinkle in the toffee bits. Stir to combine.
Grease your hands and carefully grab a 1/2 - 3/4 cup portion of the popcorn mixture out of the pot. If it's too hot, wait a couple minutes. Use your hands to press the mixture into a firm ball. Then set it on a wax paper lined baking sheet and repeat with the remaining popcorn mixture. (I like to keep the pot sitting on the stove, with the heat turned off. It helps keep the mixture warm enough to grab and manipulate.)
Melt the chocolate chips over a double-boiler or in the microwave. If using the microwave, heat on medium in 30 second increments, stirring in between, until smooth. Then pour the melted chocolate into a zip bag and snip off the corner. Use the bag to drizzle the chocolate over the tops of the popcorn balls. Allow the popcorn balls to rest until the chocolate is firm. Then wrap individually for edible gifts!