Make the cake.  Preheat the oven to 350 degrees F.  Oil a 9 by 13 inch pan.

In a large bowl, whisk together the sugar and oil.  Whisk in the eggs one at a time.

In a medium bowl, stir together flour, baking soda, baking powder, cardamom, and espresso.  Alternately add the flour mixture and coffee to the sugar mixture.  Stir until just combined.  Pour into the prepared pan, and bake 15-20 minutes.  Cool completely in the pan.

Once cool, make the glaze.  In a small, microwave safe bowl, melt the coconut butter with the maple syrup in 15 second increments in the microwave, stirring in between.  Once melted stir in the vanilla and coffee.  The icing should be thin and spreadable.  Add more coffee if it is too thick.  Drizzle over cake.  Allow to set about an hour before cutting and serving.

Bars may be stored in an airtight container for up to 3 days or frozen wrapped in parchment and foil and placed in a zipper bag for up 3 months.  Thaw at room temperature about 1 hour.