Step 1Heat the oven to 350 degrees. Grease 6 (4-ounce) ramekins with the 1 tablespoon softened butter and dust with cocoa powder; tap out excess. Melt the chocolate and butter in a double boiler or in a bowl over hot water, stirring until smooth. Remove from the heat.
Step 2In a large bowl, whisk together the eggs, yolks and sugar until well combined. Whisk in the melted chocolate mixture. Sift the cake flour over the mixture and fold in.
Step 3Divide the batter among the ramekins. Arrange the ramekins on a baking sheet and bake for 5 to 6 minutes. Rotate the pan and bake an additional 4 to 6 minutes, until the edges look set and have pulled slightly away from sides but the centers are still slightly liquid. Do not overbake.
Step 4Invert the cakes onto plates immediately and serve with the cherries.
Step 1Melt the butter in a medium saute pan. Add the sugar and stir over medium-high heat until the sugar melts and begins to turn color and caramelize, 4 to 6 minutes. Add the vanilla, zest and cherries and cook until reduced and syrupy, about 5 minutes.
Step 2Remove from the heat, add the Cointreau or Grand Marnier. Ignite the cherries and pour over chocolate cakes either while still aflame or after the flame dies out.