Preheat oven to 360 degrees F. Line two baking sheets with parchment paper or Silpat mats.
In a bowl, cream together butter, bacon grease, and sugars until fluffy, ~3 minutes, scraping down sides as needed.
Add egg and vanilla and beat another 1-2 minutes.
In a bowl, mix together flour, baking soda, baking powder, and salt. Add in stages to the wet mixture and incorporate fully.
Mix in chocolate chips.
Place tablespoon-sized balls of dough on each baking sheet. Sprinkle sea salt on top.
Bake 12-13 minutes until golden brown around the edges.
Remove and transfer cookies to a cooling rack.