In a mixing bowl, whisk the sourdough starter and whole milk until smooth and well-blended.

Cream the softened unsalted butter, granulated sugar, and vanilla extract together on medium speed for about 3 minutes.

In a separate bowl, whisk together the all-purpose flour, ground nutmeg, ground cinnamon, ground cloves, baking powder, and salt.

Gradually add the dry mixture to the wet ingredients in the stand mixer, mixing on low speed just until coarse crumbs form.

Add the sourdough mixture to the dry ingredients and mix until a soft dough forms.

Cover the dough with plastic wrap for a fermentation step, if desired.

Let the covered dough ferment at room temperature for up to 8 hours if you choose.

Fold in the diced apple and dried cranberries and chill the dough in the refrigerator for at least 30 minutes.

Preheat your oven to 350°F (175°C) while the dough chills.

Roll the dough out on a floured surface to a thickness of 1/4 to 1/2 inch.

Use a round cookie cutter to cut out shapes and place them on prepared baking sheets.

Brush the tops of the shaped cookies with a little whole milk.

Bake in the preheated oven for approximately 20 minutes.

Allow the Sourdough Soul Cakes to cool on the baking sheets before transferring them to a wire rack.

Dust the cookies generously with powdered sugar for a charming presentation.