Preheat oven to 350 degrees. (I use the convection setting on my oven.)
In a mixing bowl, add melted butter, sugar, vanilla, and brown sugar. Mix well. Mix in one large egg.
Next, measure flour using ounces. If using measuring cups, make sure to fluff up the flour before measuring, and do not pack the cups.
Add baking soda, baking powder, and salt. Mix until almost combined. Fold in chocolate chips. Try not to over mix the dough. Mix just until combined.
Scoop dough into 12 equal potrions, roll into balls, and flatten slightly. Line baking sheets with parchment paper. I like to bake 6 cookies per tray.
Bake in a preheated 350 degree oven for about 14 to 16 minutes. Keep check on browning. Baking times will vary depending on your oven. Enjoy!