First, make the brown butter. Take the butter for both (1 cup total), and cut it into cubes. Add it to a light-colored pan, if you have one, so that you can easily see when the butter has browned. Heat over medium heat, stirring consistently to prevent the butter from burning. Heat for about 5 minutes or until the milk solids have turned a golden brown color and you can smell the nutty aroma. Place a bowl on a scale and zero it out. Pour the brown butter in the bowl and divide the number by 2. Put half the butter in the refrigerator to solidify for the frosting, and use the other half in the cookie recipe.

Preheat the oven to 375℉.

In a large bowl mix half of the browned butter with the brown sugar and granulated sugar. 114 grams butter, 110 grams brown sugar, 100 grams granulated sugar

Mix in the sourdough discard, egg, vanilla extract, and molasses.120 grams sourdough discard, 1 egg, 5 grams vanilla extract, 10 grams molasses

In a medium bowl combine the dry ingredients and then add it to the wet ingredients. Mix until combined. 1 gram cinnamon, 135 grams rolled oats, 210 grams all purpose flour, 3 grams salt, 5 grams baking soda

Line 2 large cookie sheets with parchment paper or silicone baking mats.

Use a 2-tablespoon scoop to portion out the cookie dough, placing 12 evenly spaced dough balls on each baking sheet. Then, gently press them down with the palm of your hand to slightly flatten.

Bake for 5 minutes, then switch the baking sheets between racks. Continue baking for another 5 minutes, or until the edges are lightly golden. Be careful not to over bake, as this will result in a crunchier texture.

Let the cookies cool on the pan for a couple minutes and then move them to a cooling rack.

Make the frosting by whipping all the ingredients together until light and fluffy. Place the frosting in a piping bag or a ziplock bag and cut the tip. 114 grams butter, 240 grams powdered sugar, 30 grams milk, 2 grams vanilla extract, 1 gram cinnamon, 1 gram salt

Pipe the frosting in between two cookies and sandwich them together.