Preheat the oven to 350 degrees F. Line a 9x13 baking dish with parchment paper on the bottom and spray the sides with nonstick baking spray.

Start by making the chocolate crunch topping - mix together cocoa powder, brown sugar, and all purpose flour. Mix together until combined, then pour in melted butter. Mix together until crumbles begin to form. If it becomes lumpy, break up the lumps up with your hands.

Pour the crumble onto a baking sheet and bake for 8-10 minutes. Let it cool on the baking sheet, it'll harden as it cools.

Now make the cake batter. In a large mixing bowl, mix together all purpose flour, milk powder, brown sugar, sugar, baking soda, baking powder, cinnamon, nutmeg, kosher salt, and espresso powder. Whisk until combined and set aside.

In a separate bowl, mix together melted butter, vegetable oil, cocoa powder, eggs, buttermilk, and vanilla extract. Whisk together until smooth and combined. If your cocoa powder is lumpy, sift.

Pour the dry ingredients into the wet ingredients and mix until just combined, then pour in hot coffee and continue to mix until the batter is smooth, about 15-20 seconds.

Pour the batter into the prepared pan and bake for 30-35 minutes, until a wooden skewer inserted into the center of the cake comes out with just a few moist crumbs.

While the cake is baking, make the frosting. For the frosting, add butter and heavy cream to a medium saucepan over medium heat. Once the butter is melted and the cream is warmed throughout, add the chocolate chips and mix together until the chips are fully melted.

Remove from heat and add powdered sugar, cocoa powder, corn syrup, and vanilla extract. Whisk together until combined and fold in chopped pecans. Set aside.

Once the cake is out of the oven, let the cake cool for about 20 minutes, then pour the frosting on top. Once the frosting is set, add the chocolate crunch on top.