Cream together the butter and powdered sugar, then mix in the vegetable oil.
Beat in the cognac, orange juice, baking powder, and baking soda.
In a separate bowl mix together the cinnamon, ground cloves, nutmeg, pepper, and flour. Slowly add to the batter.
Stir in the chopped walnuts and ground sesame. Shape the dough into ovals. Bake at 350˚F for 22-25 minutes and let cool.
To prep the syrup, combine the honey, sugar, water, and lemon juice in a pot and heat until dissolved. In a separate bowl, mix together the 3 cups finely chopped walnuts and 1/4 cup sesame seeds.
Use a slotted spoon to dip a cooled melomakarona into the syrup. Leave submerged for about 10 seconds, then remove and roll carefully in the walnut mixture.