Pumpkin Chocolate Chip Bread with Chocolate Streusel

Preheat the oven to 325 degrees F. Line a 9 by 5-inch loaf pan with parchment paper so that there's about 2 inches overhang on both sides (this makes it easier to remove from the pan and catches any streusel that may try to run away in the oven).
Make the chocolate crumble - in a small bowl combine all purpose flour, cocoa powder, and brown sugar. Mix together then pour in the melted butter and mix until crumbles begin to form. Place into the refrigerator to firm up/cool.
In a large bowl, combine the dry ingredients - all purpose flour, baking powder, baking soda, nutmeg, cinnamon, cloves, allspice, ground ginger, and kosher salt. Whisk together then add in the chocolate chips and toss to coat. Set aside.
In a separate large bowl, combine the wet ingredients - pumpkin puree, brown sugar, olive oil, buttermilk, and vanilla extract. Whisk together until combined, about 1 minute, then fold in the flour mixture until just combined and there's no patches of flour.
Add the batter to the prepared loaf pan, then sprinkle the chocolate crumble on top (use your fingers to break up the crumble if it stiffens).
Bake on the middle rack of the oven for 1 hour and 30-40 minutes, until a toothpick inserted into the center of the loaf comes out clean or with just a few moist crumbs. (we're baking this low and slow so that it bakes evenly for optimal texture) Let the bread cool in the pan for 20 minutes, them remove onto a wire rack to cool completely.