Step 1

Heat the oven to 350 degrees. Line two large rimmed baking sheets with parchment paper.

Step 2

In the bowl of a stand mixer fitted with a whisk attachment, or using a handheld mixer, beat the peanut butter and sugar on high until creamy, about 2 minutes. Add the eggs and salt and beat on medium until well combined, about 1 minute. Transfer half the dough to a bowl or a clean work surface.

Step 3

Add the chocolate, cocoa powder and salt to the remaining dough in the bowl of the electric mixer and beat on medium until combined.

Step 4

Portion the peanut butter dough into 1 tablespoon scoops and the chocolate dough into heaping 1 tablespoon scoops. Squeeze together one scoop of peanut butter dough and one scoop of chocolate dough and roll into a neat ball. Transfer the balls to the prepared pans, at least 1 1/2 inches apart. Using the flat bottom of a glass dipped in granulated sugar, press each ball into a flat circle that is 1/2-inch thick. (After pressing the first cookie, the glass will be greasy enough for the sugar to adhere to it.)

Step 5

Bake the cookies until set and slightly puffed, 14 to 16 minutes, rotating the sheets halfway through baking. Transfer the baking sheets to wire racks to cool. (Cookies will be quite crumbly and delicate right after baking and need a few minutes to firm up.)