In a large bowl, mix together the flour, salt, baking powder, and baking soda. Set aside.

Add the butter to a heavy bottom saucepan over medium heat. Stir until melted and the butter forms brown specks at the bottom, about 5-6 minutes. The browned butter will also smell nutty when done. Remove from heat to cool down to room temperature.

In a large bowl, combine the brown sugar, granulated cane sugar, egg, egg yolk, and brown butter. Whisk vigorously for 2 minutes, until fluffy and smooth. Whisk in the vanilla and sourdough discard.

Fold in the flour mixture with a spatula.

If the mixture is still warm to touch, place in the freezer for 5-10 minutes before folding in the chopped chocolate.

Cover with Saran Wrap and let chill in the fridge for at least 2 hours to overnight.

Preheat oven to 375F. Line a large baking pan with parchment paper.

Use a melon scooper, about 1 tablespoon dough per cookie, to make the mini cookies. Roll in the palms of your hands then flatten to 1/4" thick. Evenly distribute on your prepared pan.

Bake for 5-6 minutes, until set in the centers. Let cool completely before adding the marshmallow fluff.

In a small bowl, mix the gelatin and 1/2 cup cold water together. Set aside for 10 minutes to thicken up.

Place the remaining 1 cup of water and sugar in a deep saucepan over medium heat. Stir until sugar is dissolved.

Use a candy thermometer to know when the sugar has reached 240F, then carefully remove and pour into your stand mixer fitted with the whisk attachment.

Transfer to a large piping bag, then snip off a 1/4 - 1/2" opening. Pipe tall mounds on each miniature cookie.

Let rest 30 minutes, until tacky to touch and won't fall off the cookies when turned over.

Combine the melted chocolate of choice with coconut oil to thin out in a small, deep glass.

Dip the marshmallow portion of the cookies then gently shake off any excess.

Place on a parchment paper line baking pan. Let firm up in the fridge for 20 minutes, or at room temperature for 1 hour.