Reduce heat to medium-low, stir in chocolate, chili powder, chipotle, cinnamon, and cloves; cook, stirring frequently, until spices are fragrant and chocolate is melted and bubbly, about 1 minute. Stir in garlic and cook until fragrant, about 30 seconds. Stir in broth, tomato, figs, peanut butter, and sesame seeds. Bring to simmer and cook, stirring occasionally, until sauce is slightly thickened and reduced to about 1¾ cups, 10 to 15 minutes. Transfer sauce to blender and process until smooth, about 30 seconds. Season with salt, pepper, and sugar to taste.