Preparations

• Take your eggs out of the fridge, so they can come to room temperature. Though, if you forget (as I often do) simply add it to the still slightly warm butter, to help you cool it down.
• Get all your ingredients ready. I love measuring them out in advance, so I can just throw them together, looking all organised when making the cookies. Plus I’m very prone to forgetting something. So having it all lined up helps me make sure I got it all.

Brown Your Butter

• In a saucepan, melt your butter over medium high heat. It will splatter and bubble wildly.
• The moment you hear the sound changing and the bubbles look smaller, turn down the heat to medium low and start stirring with your spatula, scraping any brown bits off the bottom of the pan. This is the good stuff, you don’t want it to burn!
• Let it brown for just a minute or so, until it smells lovely nutty and has a deep amber color. Depending on your hob this can be very quickly! In doubt stop earlier rather than burning it.
• Transfer to your heat proof bowl. Allow to cool in the fridge for about 30 minutes or until the sides are starting to solidify, but the center is still liquid.
• At this point whisk and integrate all the lovely brown bits from the bottom back in, until you have a creamy mass. You want the consistency to be scoopable and thick, like softened peanut butter.
• Don’t be tempted to use the butter in liquid form. It won’t get fluffy when mixing with the sugar and your cookies might come out flat and greasy instead of puffy and chewy.

Whisk Butter and Sugar

• Using either your whisk or the paddle attachment of your stand mixer, start whisking butter and sugar until slightly lighter in colour. It won’t get as fluffy as a white sugar mix, as the brown sugar is a bit denser due to the high molasses content.

Add Wet Ingredients and Protein Powder

• Mix in the egg, peanut butter, and vanilla, until fully incorporated and creamy.
• Add the protein powder and sourdough discard and mix again until smooth. While you could add the protein powder to the flour, I always feel it dissolves better when added with the wet ingredients.

Mix in The Dry Ingredients

• Now come the flour, baking soda and salt. Give them a brief mix while on top of the batter (or in a smaller bowl), so all is evenly distributed throughout the dough.
• Gently stir it in until just combined. Only until no dry streaks are left. Don’t overmix.

Shape And Coat Your Peanut Brown Butter Cookie Dough

• Line your sheet pans with baking parchment. I usually portion all the cookie dough onto one of them, so I can set up and easy “coating station” with sheet pans on both sides of the peanut/egg containers.
• Very roughly chop your peanuts. It’s totally fine if you have some halves in the mix.
• Transfer into a flat container or deep plate.
• Find a small bowl that fits a cookie ball being rolled in it, but not much more. Your egg for the coating goes into that and gets slightly whisked with a fork.
• Portion out all of your brown butter cookie dough, ideally with a cookie scoop. Mine was medium sized 35ml/1.18oz.
• Your cookie dough will be smooth, slightly crumbly and soft. It should hold together when gently squished in your hand, but crumble apart when more pressure is applied.
• Grab each portion of the dough and roll it into a smooth ball, finding exactly that “hold together but not crumble” pressure point. The first cookie might take a moment to figure out, but easy enough.
• Toss each of the dough balls in the egg wash, then right into the peanuts, pressing them onto the dough firmly. Again, play with the pressure point here. My first cookie crumbled a bit when pushing too firmly but easily came back together.
• Place them on the second sheet pan.

Bake Your Peanut Crunch Cookies

• Preheat your oven to 350°F/175°C.
• Arrange your cookies a few inches apart, flattening them a little, so you have about 8 evenly spaced ones on each sheet pan. They don’t spread very much.
• Bake for 10-14 minutes, rotating the tray once at around 6 minutes, as most ovens bake unevenly.
• If the tops are a bit cracked, but the dough underneath looks matte (slightly dry, not shiny and wet) and the edges are starting to brown, take them out.
• The trick here is, to have them still slightly underbaked in the center, as they will keep baking after removing from the oven.
• Allow them to cool on the sheet pan while you bake the next portion. Transfer to a cooling rack after about 5-10 minutes, using a spatula.
• These Peanut Brown Butter Protein Sourdough Cookies do need to cool completely before they are at their best, as peanuts are slightly soft when warm. So to get the full crunch factor, enjoy them cold. If you like with some milk or a nice cuppa.