Prepare the Lemon Curd Filling:

• In a medium saucepan, whisk together the egg yolks and granulated sugar until pale and slightly thickened.
• Stir in the cubed butter and lemon juice.
• Cook over medium-low heat, stirring constantly, until the butter is melted and the mixture begins to thicken and coats the back of a spoon (about 8-10 minutes). Do not boil.
• Remove from heat and stir in the lemon zest.
• Pour the lemon curd through a fine-mesh sieve into a clean bowl to ensure a smooth texture. Cover the surface of the curd directly with plastic wrap to prevent a skin from forming and refrigerate for at least 30 minutes to allow it to cool and thicken.

Prepare the Red Velvet Soufflé Batter:

• Preheat your oven to 375°F (190°C). Lightly grease and flour 4-6 individual ramekins.
• In a large bowl, whisk together the Devil's Food Cake Mix and cocoa powder until well combined.
• In a separate bowl, whisk together the buttermilk (or milk mixture), egg yolks, and vegetable oil until smooth. Stir in the red food coloring.
• In a small bowl, whisk together the white vinegar and baking soda. It will fizz.
• Add the wet yolk mixture (including the vinegar/baking soda mixture) to the dry ingredients and whisk until just combined. Be careful not to overmix; a few small lumps are okay. Stir in the baking powder.
• In a clean, grease-free bowl, beat the egg whites with an electric mixer until soft peaks form. Gradually add the 2 Tbsp of granulated sugar and continue beating until stiff, but not dry, peaks form.
• Gently fold about one-third of the whipped egg whites into the red velvet batter to lighten it.
• Then, carefully fold in the remaining egg whites until just combined and no white streaks remain. Be very gentle to maintain the airiness.

Prepare the Cream Cheese Icing:

• In a medium bowl, beat the softened cream cheese and softened butter (if using) together with an electric mixer until smooth and creamy.
• Beat in the vanilla extract (and lemon zest, if using).
• Gradually add the sifted powdered sugar, beating on low speed until incorporated and then on medium speed until smooth.
• If the icing is too thick, gradually add milk or heavy cream, one tablespoon at a time, until you reach your desired consistency for spreading or drizzling.

Assemble and Bake the Soufflés:

• Spoon about half of the red velvet batter into each prepared ramekin.
• Place a generous Tbsp of chilled lemon curd in the center of each ramekin.
• Carefully spoon the remaining red velvet batter over the lemon curd, trying to cover it completely.
• Bake in the preheated oven for 15-20 minutes, or until the soufflés are puffed up and the centers are just set. Avoid opening the oven door during baking to prevent them from collapsing.

Assemble and Serve:

• Place 2-3 warm soufflé pancakes on each plate.
• Drizzle the cream cheese icing generously over the top.
• Garnish with lemon zest if desired.

Serve immediately to enjoy their light and airy texture.