1-First Step: Cream the butter and sugars Beat softened butter, granulated sugar, and brown sugar in a large bowl with electric mixer on medium speed for 3-4 minutes. Scrape sides often. This creates airy texture for chewy chocolate cookies. Mixture turns light and fluffy, trapping air for softness.

2-Second Step: Add eggs and vanilla Beat in eggs one at a time, fully incorporating each. Add vanilla extract. Mix 1-2 minutes until smooth. Wet ingredients emulsify, preventing separation in double chocolate chip cookies.

3-Third Step: Combine dry ingredients Whisk flour, cocoa powder, baking soda, and salt in separate bowl. Gradually add to wet mixture on low speed. Stop when just combined to avoid tough cookies. Dough looks shaggy.

4-Fourth Step: Fold in chocolate chips Gently stir in chocolate chips by hand with spatula. Reserve 1/4 cup for tops if desired. Overmixing deflates dough, so keep light. Chill dough 15 minutes for thicker results.

5-Fifth Step: Scoop and bake Drop 2-tablespoon scoops 2 inches apart on sheets. Bake 9-11 minutes until edges set but centers soft. Cookies firm as cool. Rotate sheets midway for even baking.

6-Sixth Step: Cool and enjoy Cool on sheets 5 minutes, then transfer to racks. Store as below. Serve warm for best melt. Pair with ice cream for sundaes.