Assemble your ingredients and allow egg, miso, and butter to come to room temperature.

In a bowl, combine flour, baking soda and baking powder, and whisk to mix thoroughly.

In a stand mixer, using a paddle attachment, cream butter and sugar on medium speed until fluffy and well blended (~5 minutes). Scrape the bowl after 2.5 minutes of mixing.

Scrape the bowl, Add miso and peanut butter, and mix on medium speed for 2 minutes until smooth.

Scrape the bowl again, add egg and vanilla and mix on medium speed for 2 minutes again.

Add about half of the flour mixture and mix on low speed until just blended. Then, add the rest and mix until it, too, is just blended in. Do not overmix.

The batter will be fairly sticky, but should be a texture that is okay to handle. If you prefer, you can chill the batter for 20 minutes in the fridge to firm it up a bit.

Roll balls of dough that are about 1.5 inches (~3.8 cm) in diameter, then roll them in sugar before transferring to a parchment paper-lined cookie sheet. Place balls about 2 inches apart.

If you prefer, you can chill the cookies in the fridge for 2 hours or even overnight. I chose to bake them right away because I wanted to eat them. 😋. Bake them in a preheated 350°F oven for ~10 minutes, rotating the pans halfway through baking.

Store at room temperature in a sealed container.

Notes: 🍪. If you want to obtain flatter cookies, remove the cookie sheets from the oven when there are 3 minutes of cooking time remaining. Bang the sheet hard against the counter to flatten the cookies, then return to the oven to complete the cooking time. When you remove them, bang them on the counter again to complete the flattening process. This forces air out of the cookies and will give them a chewier texture.

Notes: 🍪. Rolling the cookies in coarser sugar (like Demerara) will provide more crunch. 🍪. I preferred to use creamy peanut butter, but crunchy would also work. Do NOT use natural peanut butter with separated oils.