There is no need to preheat your oven yet. Once this dough is made and balled up, it will spend some time chilling in the freezer.

1/2 cup butter

Cream the butter. I use a wooden spoon, but you can use an electric mixer if you'd like. I used unsalted butter, but I'd say use what you happen to have and adjust your salt quantity accordingly.

1/2 cup brown sugar

1/3 cup white sugar

Once your butter is looking nice and creamy, add in both the brown sugar and white sugar Mix that all together till it's evenly combined with the butter.

1 large egg

Push the mixture to one side of the bowl to make an area where you can whisk the egg. Crack the egg into the bowl and whisk the egg for about 30 seconds. Then mix your whisked egg into the butter and sugar mixture.

1 and 1/2 tsp vanilla

Add the vanilla (1 and 1/2 tsp) Mix that all together.

1 cup flour

1/2 cup cocoa powder + 2 TBS

1 tsp baking soda

1/4 tsp salt

Get your smaller bowl to mix up all the dry ingredients.
Add the flour,
cocoa powder,
baking soda,
and salt *maybe just a pinch if you used salted butter in step 1*
Then mix that all together until it's perfectly combined.

Add the dry ingredients from the smaller bowl into the larger bowl. Start mixing it all together. It will seem quite dry, but the more you work with it, it will all come together and become a thick chocolatey dough.

1 cup Reese's Pieces candies

1/2 cup semi sweet chocolate chips

Once it's all combined nicely, it's time to add the candy and chocolate chips.

Once everything is perfectly mixed up, it's time to ball up the dough. Use a spoon and your hands to get doughballs that are about 1.5 inches diameter. This recipe should make about 20 dough balls. If you want them to be perfectly sized, weigh out all the dough, divide the total weight by 20 and you can find the exact weight that each ball should be. When you have all ~20 of your doughballs formed, place them on a cookie sheet, cover them with plastic wrap and let them chill in the freezer for 1 hour.

When the dough has been in the freezer for about 30 minutes, it's a good time to get the oven preheated.
*Set your oven to °350 fahrenheit*
Let the dough continue to rest in the freezer for another 30 minutes.

At this point, the oven should be at temperature and doughballs perfectly chilled. Place the chilled doughballs on a cookie sheet lined with parchment paper, or a silcon mat. (Or if you don't have those options, lightly grease the pan with a coating a butter or cooking spray)