Using a mixer with a paddle, cream together the butter, sugar and eggs until smooth. Add the vanilla and zest and combine. Mix together the flours, salt and baking soda and slowly fold in using the paddle alternating with the sour cream. Mix until smooth, but do not over mix. Spray 8 (4-ounce) ramekins and fill halfway up with the batter. Bake in a 350 degree oven for 15 minutes until a tester comes out clean. De-mold cakes onto a rack and glaze while still warm.
Combine all and bring to a boil until completely dissolved. Pull off the heat and glaze each cake with 2 tablespoons.
In a bowl, mix the berries, mint and glaze. PLATING: Slice the cake in half. Place the bottom on a plate and cover with berries then whipped cream. Top with cake and garnish with mint sprig.