Step 1

Preheat oven to 350°F. Spread out nuts on a rimmed baking sheet. Toast until fragrant and slightly darkened, 10-12 minutes. Let cool completely. Set 1 1/4 cups nuts aside for buns.

Step 2

Melt butter in a small heavy saucepan over medium heat. Stir in brown sugar, cream, honey, salt, and orange zest, if using. Bring to a boil, reduce heat to medium, and simmer until glaze is golden brown and glossy, 3-4 minutes. Pour 1 cup of glaze into baking pan, tilting to coat bottom and sides. Set aside remaining glaze. Sprinkle 1/2 cup toasted pecans over bottom of baking pan and let cool.

Step 3

Using an electric mixer on medium speed, beat butter, sugar, cinnamon, nutmeg, and kosher salt in a medium bowl until light and fluffy, 2-3 minutes. Set filling aside.

Step 4

Punch down dough; transfer to a floured work surface. Lightly dust top with flour. Follow instructions in Cooks' Notes, for assembling buns with filling and 3/4 cup pecans. DO AHEAD: Can be made 1 day ahead. Cover and chill buns and remaining glaze separately. Store remaining pecans airtight at room temperature.

Step 5

Loosely cover pan with plastic wrap or a kitchen towel. Let buns rise in a warm, draft-free area until doubled in size, 45 minutes to 1 hour, or 1 1/2-2 hours if dough has been chilled overnight.

Step 6

Arrange a rack in middle of oven; preheat to 350°F. Whisk egg with 1/2 teaspoon water in a small bowl. Brush tops of buns with egg wash. Bake, rotating pan halfway through and tenting with foil if browning too quickly, until buns are golden brown, filling is bubbling, and an instant-read thermometer inserted into center of buns registers 185°F, about 50 minutes. Let cool for 5 minutes. Spoon remaining glaze over. Sprinkle 1/2 cup pecans over. Let cool in pan on a wire rack.

Step 7

Lightly sprinkle sea salt over. Serve buns warm or at room temperature.