Preheat your oven to 350°F (175°C) and prepare an 8-inch square metal baking pan with non-stick spray.

In a small mixing bowl, combine the brown sugar, all-purpose flour, chopped pecans, and cinnamon. Mix in melted butter until crumbly.

In a large mixing bowl, whisk together the all-purpose flour, baking powder, baking soda, fine sea salt, ground cinnamon, ground ginger, and ground nutmeg until well combined.

In a separate bowl, blend together the pumpkin puree, vegetable oil, sour cream, and beaten eggs until smooth.

Gently fold the wet ingredient mixture into the dry ingredients until just combined; do not overmix.

Pour half of the batter into the prepared baking pan and sprinkle with half of the streusel topping. Add the remaining batter and top with the remaining streusel.

Bake for approximately 35 minutes or until a toothpick inserted comes out clean. Let it cool for 15 minutes in the pan.

Whisk together powdered sugar and maple syrup to create glaze. Drizzle over the warm cake and slice into squares.