Step 1: Preheat oven to 350. Add butter and sugars to the bowl of a stand mixer. Mix on high until combined, light, and fluffy.
Step 2: Add vanilla and eggs and mix until just combined.
Step 3: In a separate bowl, combine flour, baking soda, and salt.
Step 4: Add the dry ingredients to the wet ingredients a little at a time, mixing in between.
Step 5: Set aside some chocolate chunks to press into the top. Add the rest to the dough and fold in.
Step 6: Place baking cups on a baking sheet. You should be able to fit about 8 cups to one baking sheet – you want there to be plenty of space between each one. Fill each cup with three heaping scoops of dough.
Step 7: Press the dough down into the bottom of the cup. Press a few chocolate chunks into the top of each cup of dough.
Step 8: Bake for 22-24 minutes. Do not over-bake. You want the edges to be golden-brown but the middle to still be a little gooey. Serve warm.