Prep Pan & Oven: Preheat oven to 350°F (175°C). Grease an 8.5x4.5-inch or 9x5-inch loaf pan and line with parchment paper with overhang for easy release.

Toss Apples: In a small bowl, toss diced apples with 2 tablespoons brown sugar and 1 1/2 teaspoons cinnamon until glistening. Set aside.

Whisk Dry Ingredients: In a medium bowl, whisk together flour, baking soda, baking powder, salt, and ground nutmeg.

Mix Wet Ingredients: In a large bowl, whisk melted butter, granulated sugar, and brown sugar until glossy. Whisk in eggs one at a time, followed by Greek yogurt and vanilla extract until smooth.

Combine Batter: Fold dry ingredients into wet batter with a spatula just until combined (do not overmix). Gently fold in half of the spiced apple chunks.

Layer & Swirl: Spread half the batter into prepared loaf pan. Scatter remaining spiced apples over the center, then top with remaining batter. Smooth top with an offset spatula.

Bake to Golden: Bake at 350°F for 50 to 55 minutes until a wooden toothpick inserted into the center comes out clean or with a few moist crumbs. Tent with foil at 35 minutes if browning too quickly. Cool in pan for 15 minutes, then lift to wire rack.

Glaze & Slice: Whisk powdered sugar, maple syrup, cream, and flaky sea salt into a smooth glaze. Drizzle generously over the warm loaf. Let glaze set for 10 minutes before slicing.