Whisk together baking soda, flour, and salt. Set the bowl aside.

Bring out your mixer and add the butter. Beat it for about a minute at high speed till creamy. Switch it up to medium-high and mix in brown sugar + ¼ cup of granulated sugar. Beat for 2 to 3 minutes.

Crack in the large egg and whip until well combined. Scrape the bowl to make sure nothing is left out. Toss in the creamy peanut butter and a teaspoon of vanilla extract and mix again.

Slowly add your dry ingredients (from Step 1) to the wet ones (Step 3) and mix at low speed 'til combined.

Cover the dough and let it chill in the fridge for an hour or two (or 3 days if you plan ahead).

Preheat your oven to 350°F and line your baking sheets with silicone mats or parchment paper.

Pour the remaining sugar (½ cup) into a medium bowl. Take your chilled dough and roll it into balls, each one about a scant tablespoon.

Roll these cookie dough balls in the sugar until nicely coated. Place them on your prepared baking sheets, spacing them about 2 to 2.5 inches apart.

Using a fork, make a crisscross pattern on top of each cookie. Use your fingertips to reshape them into nice, thick discs.

Bake them for 10 to 15 minutes until the edges look set and lightly browned. Don't worry if the centers still seem super soft.

Let them sit on their baking sheet (out of the oven) for 5 minutes. Transfer them to a rack to chill entirely. Slice and serve!