Preheat your oven to 350 degrees Fahrenheit. Grease three 6-inch cake pans with non-stick spray and line the bottoms with parchment paper rounds.
In a medium bowl, whisk together the flour, baking powder, baking soda, and salt. Set aside.
In a large mixing bowl, cream together the butter and sugar until light and fluffy.
Dissolve the instant coffee in the vanilla extract. Add the eggs and the vanilla/instant coffee mixture to the butter mixture and mix until smooth.
Alternate adding the dry ingredients and the buttermilk to the butter/coffee mixture, mixing until just combined.
Fold in the shredded carrots until evenly distributed.
Divide the batter evenly among the prepared cake pans and bake for 27-31 minutes, or until a toothpick inserted into the center comes out clean. Let cool completely.