Fill a wide pot with at least 1 ½ inches of water, with a thick ring of crumpled tinfoil placed on the bottom to act as a "booster seat" that will prevent the bowl from touching the bottom of the pot. Place over high heat until steaming-hot, then adjust temperature to maintain a gentle simmer.

Combine egg whites, sugar, salt, cream of tartar, and vanilla seeds (if using) in the bowl of a stand mixer. Set over steaming water, stirring and scraping constantly with a flexible spatula, until egg whites hold steady at 185°F (85°C). This should take only 10 to 12 minutes, so if mixture seems to be moving slowly, simply turn up the heat. Once ready, transfer to a stand mixer fitted with a whisk attachment and whip at high speed about 10 minutes, until meringue is glossy, stiff, and cool to the touch, around 90°F (32°C).

With mixer still running, add butter, 1 or 2 tablespoons at a time. Initially, the volume of the meringue will decrease dramatically; it may even seem soupy along the way, but as the cool butter is added, the mixture will begin to thicken and cool. In the end, buttercream should be thick, creamy, and soft but not runny, around 72°F (22°C). Mix in vanilla extract on low speed until well combined. Then mix in the cranberry jam on low speed.

Place chocolate in a small, heatproof bowl.

In a 1-quart stainless steel saucepan heat cream and dried cranberries over medium-low heat to warm for 5 minutes, then increase to medium-high heat until it has reached a simmer and started to bubble hard around the edges. Use a slotted spoon or spider to remove the cranberries from the cream, and immediately pour hot cream over chocolate and let stand 1 minute. Using a spoon, stir until smooth.

Preheat the oven to 350° and line three 8” by 2” cake pans with parchment rounds; grease lightly.

Roughly chop the chocolate and place in a medium bowl; sift the cocoa powder over top. Meanwhile, bring the cranberry juice to a simmer in a 3 quart stainless steel pot. When it begins to bubble, shut off the heat and add the chocolate/cocoa all at once. Whisk to form a smooth paste, then stir in the rose flower water.

Using the same bowl and sieve from before, sift the flour and set aside.

In the bowl of a stand mixer fitted with a whisk attachment, combine the sugar, baking soda, baking powder and salt. Add the eggs and mix for a minute on low speed to moisten. Increase the speed to medium and whip until fluffy and light, about 8 minutes.

Reduce speed to medium-low and splash in the melted butter a little at a time, then whip in the chocolate-cranberry paste. When well combined, reduce speed to the lowest setting. Add one-third of the flour followed by one-third of the milk, alternating between the two until completely incorporated.

Stir the batter once or twice with a flexible spatula, then divide between the prepared pans (27 ounces each). Bake until the cakes are puffed and somewhat firm to the touch, though your finger may leave a slight impression; about 40 minutes.

Let the cakes stand at room temperature for 10 minutes, then loosen the edges with a knife, invert onto a wire rack, and cool until no trace of warmth remains. I like to leave the pans on top; it takes longer to cool this way, but traps steam to retain moisture.

Level the cakes with a serrated knife. Top each with a heaping cup of freshly whipped Cranberry Buttercream and spread into an even layer.

Leave the sides exposed for a rustic look, or give the cake a crumb coat and fully frost.

Finish with a swirl of plain or Cranberry Ganache. The spiraled edges give an illusion of the cake being much taller than three layers.