Heat your oven to 350°F. Grease a 9-by-5-inch loaf pan with nonstick cooking spray and set aside.
In a medium bowl, whisk together the flour, cocoa powder, pumpkin pie spice, baking soda, and sea salt. Set aside.
In a large bowl, combine the pumpkin puree, brown sugar, oil, buttermilk, eggs, and vanilla extract. Stir until smooth and combined.
Stir the dry ingredients into the wet ingredients, don’t overmix. Stir in 3/4 cup of the chocolate chips.
Pour batter into prepared pan. Sprinkle the remaining 1/4 cup of chocolate chips over the top of the bread. Bake for 50-60 minutes, or until a toothpick inserted into the center of the bread comes out mostly clean, you might have some melted chocolate chips on the toothpick and that is fine. You just don’t want a lot of gooey batter. Oven times will vary so make sure you check it at 50 minutes to be safe.
Remove the pan from the oven and set on a wire cooling rack. Let the bread cool in the pan for 15 minutes. Run a knife around the edges of the bread and carefully remove from the pan. Let the bread cool on the wire cooling rack until slightly warm. Cut into slices and serve.
Note-the bread will keep on the counter, wrapped in plastic wrap, for up to 4 days. This bread also freezes well. To freeze, cool the bread completely and wrap in plastic wrap and aluminum foil. Freeze for up to 1 month. Defrost before slicing.