Step 1

Make the Streusel topping and filling first and set aside.

Step 2

In a medium-size bowl whisk together the flour, chopped pecans, brown sugar, and and kosher salt. Stir in the melted unsalted butter until use combined.

Step 3

The crumb mixture will absorb the butter as it sits and will be more crumbly by the time you're ready to put it on as the final layer.

Step 4

In a small-sized bowl mix together the brown sugar, cinnamon, and cocoa powder until evenly combined. Set aside until you make the cake batter.

Step 5

Preheat the oven to 350℉. Line an 8-inch square metal baking pan with parchment paper making the edge 1 ½ higher than the edge. Allow the sides to overlap. Spray the paper with the vegetable oil plus any of the pan that is showing. Set aside **(see notes)

Step 6

In a large bowl, whisk the oil, sour cream, molasses, eggs, vanilla, brown sugar, pumpkin puree, spices, salt, baking powder, and baking soda until smooth.

Step 7

Using a rubber or silicone spatula, fold in the flour, mixing just until smooth and completely combined. Do NOT overmix.

Step 8

Spread half the batter into the prepared par, smoothing it all the way to the edges.

Step 9

Sprinkle the Filling Layer mixture evenly over the top of the bottom layer.

Step 10

Next spread the remaining batter over the top of the filling mixture.

Step 11

Sprinkle the streusel topping evenly over the top cake layer in the pan.

Step 12

Bake for 55 to 60 minutes, or until the crumbs are a golden brown and don't look wet. A toothpick or a cake tester will come out clean when inserted in the center of the coffee cake.

Step 13

Remove the cake from the oven and place it on a wire rack to cool.

Step 14

In a medium-sized bowl whisk together the confectioners' sugar, maple syrup, milk, and vanilla. If the mixture is too thick to drizzle, add a bit more milk until you reach the desired consistency.

Step 15

Drizzle on top of the crumb cake and let set about 5 minutes.

Step 16

Cool the coffee cake completely before removing it from the pan, slicing in squares, and serving. Serve with your favorite coffee or tea.