Combine butter and sugars in a stand mixer and beat on medium for 2 to 3 minutes. Scrape the sides of the bowl, add peanut butter and corn syrup and beat for another 2 minutes. Scrape the sides again, add egg yolk and vanilla and beat for 1 full minute.

Add flour, baking soda, baking powder and salt and mix at low speed until the white streaks of flour are gone. Using a broad spatula, fold in chocolate chips until they’re distributed evenly. Cover the bowl and chill for 1 to 2 hours.

When you’re ready to bake the cookies, preheat the oven to 375° F. Line two baking sheets with parchment paper. Scoop the dough into 2-inch balls (about 1 1/2 tablespoons) and place them a few inches apart. Flatten the balls slightly with the palm of your hand.

Bake for 9 to 10 minutes. The edges should be slightly darker brown but the centers should look a little soft. Leave them to cool slowly on their baking sheets, then store at room temperature for up to 3 days or freeze and store for up to 1 month.

Special notes:

Adding a liquid sweetner to this recipe helps these very rich cookies hold together and gives them a slightly chewy texture. We suggest organic corn syrup. If you prefer, you can substitute a mild-tasting honey, although the flavor will be different.