Preheat your oven to 350°F (180°C). Lightly grease a bundt pan with vegetable oil or nonstick spray.
In a clean mixing bowl or stand mixer, add the aquafaba. Beat with electric beaters or the whisk attachment on high speed until stiff peaks form (about 3–5 minutes).
In a separate large bowl, whisk together the brown sugar, vegetable oil, pumpkin purée, and vanilla extract until smooth and well combined.
Gently fold the whipped aquafaba into the wet mixture in three additions, being careful not to deflate it.
In another bowl, sift together the flour, baking powder, baking soda, salt, cinnamon, nutmeg, and ginger.
Add the dry ingredients to the wet ingredients. Stir with a wooden spoon or spatula until just combined—do not overmix.
Pour the batter into the prepared bundt pan and smooth the top.
Bake for 45–55 minutes, or until a skewer inserted into the center comes out clean. If not done, bake for an additional 5–10 minutes, checking carefully.
Let the cake cool in the pan for 10 minutes. Place a wire rack over the top of the bundt pan and carefully invert to release the cake. Let cool completely on the rack.
To make the glaze, whisk together the melted vegan butter, maple syrup, cinnamon, salt, powdered sugar, and vanilla extract in a medium bowl until smooth.
Once the cake is fully cooled, drizzle the glaze over the top and sprinkle with chopped pistachios (optional).