Preheat the oven to 375°F. Line a baking sheet with a silicone baking mat or parchment paper. Set aside.
Beat the butter for about 30 seconds with a hand held mixer in a medium sized mixing bowl. Add the brown sugar and cream for 1-2 minutes until fluffy and fully incorporated.
2 Tbsp. unsalted butter, cold, 3 Tbsp. brown sugar
Add in the egg and vanilla and combine with a silicone spatula until smooth.
1 Tbsp. egg*, whisked, 1/2 tsp. vanilla extract
Add in all dry ingredients and chocolate chips and stir to combine. The dough will appear crumbly. Without over mixing, work it together with your hands and roll into a ball.
1/4 cup + 1 Tbsp. all purpose flour, 3 Tbsp. cake flour, 1/4 tsp. cornstarch, 1/8 tsp. baking soda, 1/8 tsp. baking powder, 1/8 tsp. salt, 1/4 cup chocolate chips
Place on the prepared baking sheet and add a few more chocolate chips on top, if desired. (I keep my cookie dough in a nice round ball for a thick cookie, but you can flatten a bit if you'd prefer!)
Bake for 13-15 minutes, or until the tops and edges are golden brown but the inside is still slightly ooey gooey!
Rest on the baking sheet for 15-20 minutes before digging it. Garnish tops with sea salt flakes (optional). Enjoy as is or with vanilla ice cream!
sea salt flakes (optional)
Video
Notes
To get 1 Tbsp. of egg, whisk an egg in a small dish and measure out 1 Tbsp. of the whisked egg. Store the leftover egg in the fridge and when you're making scrambled eggs or anything you need an egg for!
Due to the nature of this cookie being a thick giant cookie, it doesn't spread very much. If you want a thinner cookie, you can try melting the butter, although I haven't tested this recipe that way to know for sure the results.