Melt chocolate, stir in butter, add vanilla and set aside.
Whip eggs until light and fluffy, gradually adding the sugar a little at a time.
Fold melted chocolate mixture gradually into whipped egg mixture.
Fold flour mixture gradually into this batter and pour into pans that have been buttered and lined with parchment paper.
Spread chunks of chopped El Rey Dark Chocolate across the surface pushing in slightly, and bake at 350 degrees for about 15 minutes.