Preheat your oven to 350°F (175°C). Lightly butter a 9×5-inch loaf pan and line it with parchment paper, leaving long ends to lift the bread out later.
In a stand mixer, cream together the brown sugar and butter until light and fluffy, about 5 minutes, making sure there are no lumps in the sugar.
Add the eggs one at a time, beating well after each addition until fully incorporated. Continue to beat for another 2-3 minutes until the batter is light and fluffy.
In a separate bowl, whisk together the flour, baking powder, salt, cinnamon, allspice, nutmeg, and cloves.
Add the dry ingredients to the mixer alternately with the buttermilk, starting and ending with the dry ingredients. Mix until just combined, being careful not to overmix.
Gently fold in the diced peaches by hand.
Pour the batter into the prepared loaf pan and spread it evenly. Sprinkle the top with coarse sparkling sugar.
Bake on the center rack for 50-55 minutes, or until the bread has fully risen and a toothpick inserted near the center comes out with moist crumbs (but no wet batter).
Let the bread cool in the pan for 10 minutes, then lift it out using the parchment paper handles. You can slice the bread while it’s still warm or wait for it to cool completely.