Make the cake.  Preheat oven to 350 degrees F/325 degrees F convection.  Oil a 9 by 13 inch pan.

In a large bowl, beat oils, sugar, and vanilla until well combined and lightened in color and texture.  Beat in the eggs one at a time followed by half of the flour.  Stir in the milk, then finish the batter with the remaining flour and baking soda and powder.

Pour half the batter into the prepared pan, then drizzle with half the caramel.  Gently swirl it in.  Pour the remaining batter over the caramel, then pour over the rest of the caramel and gently swirl it in.  Bake for about 30 minutes until golden and risen and a toothpick inserted in the center comes out clean or with a few crumbs.  Cool completely in the pan.

When the cake is cool, make the frosting.  In a medium microwave safe bowl, place the carob or cocoa powder, sugar, espresso, honey, cream, salt, and carob or chocolate.  Microwave on high in 30 second increments, stirring in between, until fully melted.  Stir in the butter and vanilla.  Pour over the cake and allow to set for at least 30 minutes before slicing and serving.  Cake may be stored in an airtight container at room temperature for up to 3 days or frozen, wrapped in parchment and foil and placed in a zipper bag, for up to 3 months.  Thaw in the microwave about 1 minute.