In a large mixing bowl, combine melted butter, brown sugar, egg, and maple extract, whisking until smooth. Create a buttermilk by mixing milk with lemon juice and letting sit for 5 minutes. Press excess moisture from pumpkin puree and stir into wet ingredients.

In a separate bowl, whisk together flour, baking powder, baking soda, salt, cinnamon, nutmeg, ginger, and ground cloves. Slowly incorporate dry mixture into wet, gently folding until just combined. Avoid overmixing.

Preheat oven to 350°F (175°C). Lightly grease mini muffin tin. Fill each cavity about 3/4 full with batter. Bake for 10-12 minutes or until a toothpick inserted comes out clean and tops are golden. Let cool slightly.

Melt butter in a small bowl. In another bowl, mix together granulated sugar, cinnamon, and cardamom. Dip each warm donut hole in melted butter, then roll in the cinnamon sugar mixture.

For an optional cream cheese dip, beat softened cream cheese with powdered sugar until smooth. Gradually mix in maple extract and enough heavy cream to reach desired consistency. Serve warm donut holes with dip.