Preheat the oven to 350 F.

In a medium bowl, whisk together the flour, baking soda, baking powder, and pumpkin spice. 

In a separate bowl of a stand mixer with a whisk attachment, add the brown sugar, olive oil, and eggs. Whisk over medium speed until the mixture is light and fluffy, around five minutes. 

Turn off the mixer and add the sour cream and pumpkin puree. Whisk again for a couple of minutes. Turn off the mixer again and add the flour mixture. Turn on the mixture for just another minute or so, until everything comes together.

Right before you are ready to bake the cake, prepare the bundt pan: Generously spray the inside of the bundt pan with the oil spray. Now sprinkle the can of sugar all around and knock out any excess in the sink. Pour in the batter, using a spoon or spatula to help guide you around the center of the pan. Bake for one hour, or until a paring knife inserted comes out clean.

Let the cake rest in the pan for 15 minutes before inverting it onto a cake stand or a cooling rack. Let the cake cool completely before pouring on the glaze.

After the cake is cool, make the glaze (so it doesn’t harden):  In a small saucepan over medium heat, melt the butter. Let it start to bubble until the color shifts from golden yellow to golden brown. When folks first make brown butter it can be tempting to stop as soon as you see the color start to change. I encourage you to keep a close eye on the butter, but let it deepen just a shade or two more. We don’t want it to turn black and burn, but your patience will be rewarded if you can hold out for a deeper brown, trust me. Turn off the heat and carefully pour the brown butter into a bowl or pitcher. Whisk in the maple syrup and powdered sugar until smooth. The glaze should be thick but pourable.  

Pour the glaze over the top of the cake, slowly turning the cake stand or plate as you go. Wherever you want the glaze to drip down, just slightly pause moving the cake stand before continuing around to glaze the entire cake.