Preheat the Oven: Preheat the oven to 350°F.
Prepare the Loaf Pan: Grease a 9×5-inch loaf pan thoroughly.
Prepare the Plums: Chop or dice the plums and set them aside, reserving a few pieces to place on top of the batter later.
Prepare the Pecans: Chop the pecans and set them aside.
Combine the Wet Ingredients: In a large mixing bowl, whisk together the egg, honey, white sugar, and vanilla until combined.
Add Applesauce and Yogurt: Mix the applesauce and Greek yogurt into the egg mixture until everything is well combined.
Add the Dry Ingredients: Stir in the flour, baking soda, salt, cinnamon, and cardamom until incorporated.
Fold in the Fruit and Nuts: Gently fold the chopped pecans and most of the chopped plums into the batter, keeping the reserved plum pieces aside for the topping.
Fill the Pan: Transfer the batter to the greased loaf pan and spread it into the pan. Gently arrange the reserved plum pieces over the top.
Add the Sugar Topping: Sprinkle the coarse sugar over the batter if desired.
Bake the Bread: Bake at 350°F for 50–65 minutes, or until a toothpick inserted into the bread comes out clean.
Cool in the Pan: Place the loaf pan on a cooling rack and allow the bread to cool for 15 minutes.
Cool Completely: Remove the bread from the pan and allow it to cool completely on the cooling rack.
Store Leftovers: Wrap any leftover bread in plastic wrap and store it on the counter for 2–3 days.