Preheat oven to 350°F. Line two baking sheets with parchment or silicone mats—this yields a golden bottom without sticking.

In a medium bowl, whisk flour, baking soda, and salt until evenly blended; set aside.

In a large bowl, beat butter, granulated sugar, and brown sugar with a sturdy wooden spoon or hand mixer on low. Scrape sides; mix until pale and fluffy (about 2 minutes).

Stir in the whole egg, yolk, and vanilla until just combined. A quick tip: pause when you see streaks of butter—that’s your cue to switch to gentle folding.

Dollop Greek yogurt and gently fold to keep the dough light—you want air, not density.

Add the flour mixture in two additions, folding until no white streaks remain. Overmixing can toughen cookies, so stop once it’s almost uniform.

Sprinkle in chips or chunks, folding just until they’re nestled in—don’t overwork or you’ll warm the dough.

Transfer dough to a bowl, cover, and chill 20–30 minutes. This step solidifies fats, so cookies spread less and bake up taller.

Use a 1½ Tbsp cookie scoop (or two spoons) to portion; place dough balls 2 inches apart. Bake 10–12 minutes until edges are light golden—centers may look slightly underdone, that’s perfect.

Let cookies rest 5 minutes on the sheet, then transfer to a rack. Sprinkle sea salt if you dare (and why not?).