Preheat the oven to 350°F. Line two sheet pans with parchment paper.
Cream the butter with the granulated sugar and brown sugar until light and aerated.
Add the eggs and vanilla and mix until combined.
Add the flour, sourdough powder, baking soda and salt, mix to combine. Add the mini chocolate chips and mix until combined.
Use a small scoop or tablespoon to scoop the dough into balls. Set the cookie-dough balls onto the prepared pans, leaving 2" between the cookies.
Bake until the edges of the cookies are beginning the brown and the center is still soft, about 7-8 minutes. Flip and trays half way through baking to help them bake evenly.
Cool on the pan about 5 minutes until firm enough to transfer to a wire rack to finish cooling.
Notes
If measuring the flour by volume use the “dip & sweep” method. That is, dip the measuring cup into the flour bin, overfill it, then sweep away the excess.