Pre-heat oven to 350F. Lightly oil 2 6" round cake pans and line the base with a parchment paper circle. Set aside. (Note: if you prefer, use an 8"x8" square pan or a pan of a similar size for a sheet cake instead of a layer cake).
Process all wet cake ingredients into a puree in a food processor (as smoothly as you can). Add in dry ingredients and process again to blend the mixture together. Divide the cake batter between the two prepared pans. Bake in a pre-heated oven for 40 mins, or until a skewer inserted in the center comes out dry. Remove from oven and cool completely on a cooling rack.
While cake is baking, prepare the frosting by melting the chocolate on a double boiler. Remove chocolate mixture from heat, stir in remaining frosting ingredients and stir vigorously to combine. The mixture will be soft / runny at this point, so place it in the freezer until ready to frost to firm up a bit (for an hour or so, or until you get to your desired consistency). When the cake is cooled, check on the frosting -- if it is too firm, simply re-warm it for a few minutes on a double boiler, stirring as it softens, until it reaches a good spreadable consistency.
Assembly: Place the first cake layer on a plate (or serving tray). Spread about half the frosting evenly (leaving about 1/2 an inch all around the edges unfrosted). Cover with the second cake layer and press down gently in the center to set the cake. Then frost the top with the remaining cake frosting. (Alternatively, you can just divide the frosting between the two cake layers, and frost the top of each evenly. Then layer one over the other). Place the cake in the refrigerator for about 30 mins for the frosting to settle. Then enjoy! (Store leftovers in the fridge).