Brown the Butter
Place butter in a light-colored saucepan over medium heat. Allow butter to melt completely, then continue cooking, swirling occasionally. Watch carefully as the butter foams, then turns clear, and finally develops golden-brown specks and a nutty aroma (about 5-7 minutes). Immediately remove from heat and transfer to a heat-proof bowl, scraping all browned bits. Reserve 2 tablespoons for the glaze if using, then allow the remainder to cool for 10 minutes.Prepare Your Workspace
Preheat your oven to 350°F (175°C). Grease a 9x5-inch loaf pan and line with parchment paper, leaving an overhang for easy removal. Measure all ingredients before starting to ensure smooth preparation.Mix Dry Ingredients
In a medium bowl, whisk together flour, baking soda, salt, cinnamon, nutmeg, and cloves. Mix thoroughly to ensure even distribution of spices and leavening agents.Prepare Wet Ingredients
In a large mixing bowl, combine cooled brown butter with both sugars. Beat until well incorporated and slightly lightened in color. Add eggs one at a time, mixing well after each addition. Stir in buttermilk and vanilla until smooth.Combine Wet and Dry Mixtures
Gradually add dry ingredients to wet ingredients, stirring just until combined. Avoid overmixing, which can develop gluten and create a tougher bread.Add Apples and Nuts
Fold in diced apples and nuts (if using) until evenly distributed. Transfer batter to prepared loaf pan and smooth the top with a spatula.Bake to Perfection
Bake in preheated oven for 55-60 minutes, or until a toothpick inserted in center comes out with a few moist crumbs. Cover loosely with foil after 40 minutes if top is browning too quickly.Cool and Glaze
Allow bread to cool in pan for 15 minutes. Use parchment overhang to lift bread out onto a cooling rack. If glazing, mix powdered sugar, reserved brown butter, and milk until smooth. Drizzle over bread when it's still slightly warm.