Preheat the oven to 400°F.
To make the batter: In a large mixing bowl, add the melted butter, light brown sugar, sourdough discard, and egg. Mix tougher using a hand mixer until combined.
Add in the yogurt, milk, flour, baking powder, cinnamon, salt, ginger, all spice, cardamom, cloves, and black pepper in that order. Mix on low until a stiff dough forms. Transfer to a piping bag with no tip.
To make the topping: In a medium bowl, add the melted butter, flour, cane sugar, light brown sugar, and cinnamon. Mix together with a spatula until a paste texture forms.
Lightly grease two donut pans with olive oil cooking spray to prevent sticking. Pipe the donut batter into the pans, this makes 10 donuts.
Crumble the topping on top of the donuts. Bake for 10 to 14 minutes or until a toothpick inserted in the center come out clean the topping looks golden brown. Allow to cool completely in the pans.
To make the glaze: In a small bowl, add the powdered sugar and mix. Whisk together until a smooth glaze forms.
Drizzle the glaze over the tops of the donuts.
Store in an airtight container for up to 3 days.