With an electric mixer, cream together butter, avocado, and sugars on medium-low speed for 1-2 minutes until very smooth. Add egg and vanilla, and mix on low speed until combined.
Add flours, baking soda, and salt. Mix on medium-low speed until dry ingredients are incorporated. Stir in chocolate chips on low speed or by hand.
Using a medium cookie scoop (or rounded tablespoons), dish balls of cookie dough about 1″ apart onto baking sheets lined with silicone mats or parchment paper. Press the balls into a cookie shape (the cookies will not change shape during baking).
Bake in preheated oven for 12-15 minutes, until bottom edges are starting to brown. Cool on baking sheets for a few minutes, then transfer to a wire rack to cool completely.
You can use all white flour and substitute brown sugar for the raw sugar if desired.