Position an oven rack to the lower third of the oven and preheat it to 325°F. Generously spray a 10-inch Bundt pan with nonstick cooking spray.
To make the cake batter, in a medium bowl, whisk together the flour, cinnamon, baking soda, salt, nutmeg and ginger.
In a large bowl, whisk together the pumpkin, oil, organic brown sugar, buttermilk, eggs, and vanilla extract until smooth. Stir in the apple bits. Fold in the flour mixture until well-blended.
To make the streusel, in a medium bowl, whisk together the flour, organic turbinado, and salt. Add the butter bits and work into the flour until the streusel is nubbly in texture and holds together when you grab a small handful in your fist. Fold in the pecans.
To assemble the cake, Pour about a third of the batter into the prepared pan. Layer over half the streusel. Repeat the layering process one more time, and then finish it off with the final third of the batter.
Bake until the cake is begins to pull away from the sides and a toothpick inserted deeply in the center of the cake comes out clean, 80 to 90 minutes. (If at any point the cake comes too brown, cover with aluminum foil.) Let cool completely in the pan set on a wire rack. To serve, invert the cake onto a serving platter and dust with organic powdered sugar. Store at room temperature for up to 3 days.