Preheat oven to 350°F (175°C). Grease and flour a 9x5-inch loaf pan or line with parchment paper. If making mini-loaves, reduce bake time by 10–15 minutes.

Roast fresh pumpkin if using: halve a small sugar pumpkin, scoop seeds, drizzle with oil, and roast cut-side down on a tray at 400°F for 30–40 minutes until tender. Scoop flesh and puree. For canned pumpkin, drain if watery.

In a medium bowl, whisk together flour, baking powder, baking soda, cinnamon, nutmeg, cloves, and salt.

In a large bowl, whisk eggs with sugars until slightly frothy. Add pumpkin puree, yogurt (or sour cream), oil (or melted butter), and vanilla. Mix until smooth.

Gently fold the flour mixture into the pumpkin mixture until just combined.

In a small bowl, mix brown sugar, cinnamon, melted butter, and optional nuts or dried fruit until paste-like.

Spoon half batter into prepared pan; dollop the cinnamon mixture and swirl it in slightly. Top with remaining batter and smooth.

Bake for 50–65 minutes; check doneness with a toothpick or thermometer (200–205°F).

Cool in the pan for 10-15 minutes, then invert onto a cooling rack to cool completely.

Whisk powdered sugar with milk and a dash of vanilla to make a glaze. Drizzle over cooled loaf.