To achieve the perfect meringue, use only fresh eggs at room temperature. It’s also crucial to carefully separate the egg whites from the yolks, as even a tiny drop of yolk can ruin the meringue's texture and make it less stable.
For the cream, it's best to use crème fraîche with 35% fat content instead of the usual pastry cream (33%) or sour cream (20%). This will result in a thicker consistency, as noted by Shuba.
for the filling:
for the meringue:
Making the meringue. First, separate the egg whites from the yolks. In a clean, dry bowl, whisk the egg whites until stiff peaks form. Gradually add the sugar, one teaspoon at a time, continuing to whisk until the mixture becomes thick and glossy. Finally, add the lemon juice, cocoa powder, and potato starch, carefully mixing until smooth.
Preheat the oven to 160°C. Line a 27×33 cm baking tray with parchment paper. Evenly spread the egg white mixture over the parchment using a spatula.
Place the tray in the preheated oven and bake for 10 minutes. Then, reduce the temperature to 110°C and bake for an additional 30 minutes.
Dust the parchment with cocoa powder using a fine sieve. Flip the baked meringue onto the cocoa-dusted sheet and let it cool for 10-15 minutes.
Making the chocolate cream. Melt the chocolate in a double boiler or microwave. Add the crème fraîche 35% and gently stir until smooth. The crème fraîche should not curdle and should have a thick creamy consistency. Place the cream in the refrigerator until completely chilled, then whip with a mixer until fluffy.
Spread the chocolate cream over the meringue layer, leaving 1-2 cm on the sides. Evenly distribute the cherries on top – whether thawed, canned, or fresh.
Carefully roll the meringue into a log using the parchment paper, and dust with cocoa powder through a fine sieve. Refrigerate the log for 2 hours to stabilize.