Preheat the oven to 350°F / 175°C. Butter and line an 8" cake pan* with parchment paper.
Heat up the milk in a small microwave-safe measuring cup. Mix in the coffee grounds then set it aside.
In a small bowl, whisk together the flour, baking powder, salt, and gingerbread spice. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, or with a hand mixer, beat together the butter, oil, sugar and molasses for 5 minutes, until light and fluffy.
Scrape down the sides of the bowl, then beat in one egg until it's well combined. Then, add in the next egg and vanilla and beat until well combined.
Fold in ½ of the flour mixture until just combined. Place a fine mesh sieve over the bowl and pour the coffee-milk mixture through the sieve to remove all of the coffee grounds. Then, add in all of the sour cream and gently mix the batter together until all of the sour cream and milk is incorporated.
Fold in the remaining flour mixture until just combined.
Pour the cake batter into the prepared cake pan. Bake for 40-45 minutes, or until a toothpick inserted in the center of the cake comes out clean.