Refrigerate the mixed dough for 15-20 minutes before baking to prevent excessive spreading and achieve thicker, chewier cookies with defined edges.

Lightly toast walnuts in a 350°F oven for 5-7 minutes before adding to the batter to intensify their nutty flavor and add a subtle crunch that complements the soft cake texture.

Slightly warm the vegetable oil before mixing to help it emulsify better with eggs, creating a more cohesive batter that yields uniform texture throughout all cookies.

Fold in chocolate chips and walnuts gently at the end—overmixing develops gluten and makes cookies tough instead of tender and cake-like.

Remove cookies when the edges are set but the center still looks slightly underdone; they'll continue cooking on the warm baking sheet for the perfect fudgy, chewy texture.