• Preheat oven to 345
• Grease a 26 cm or 10 in springform pan then line the bottom with parchment paper.
• In your mixing bowl, combine the baking mix (the biggest envelope), butter, and eggs. Mix on low until combined... then mix on high for 3 minutes. (Scrape the sides from time to time)
• Pour the batter into the prepared pan, spread to smooth.
• Bake 30 minutes
• When finished, let sit for a few minutes, then release the springform (use a knife to loosen the edges if needed).
• Remove cake from the pan, then, while still on the parchment paper, set it on a cooking rack to cool completely

Filling:

• Remove the parchment paper from the bottom of the cake, and set it on your serving plate.
• Carefully, use a serrated knife to split the cake in half horizontally. (Stick toothpicks in around the edge to guide you if you are worried about staying level)
• Set the top aside for a moment
• Put the cleaned ring from the springform pan around the base on the plate.
• Now make the filling.
• In your mixing bowl, whip the cold heavy cream until stiff (not TOO stiff... you want it stable, not turning into butter). Set aside for a moment
• Put the warm water (warm, not hot) in a medium bowl, add the contents of the middle sized packet. (It's mostly gelatine, sugar and flavoring. Use a whisk and beat until everything is dissolved (you can't feel the sugar crystals against the bowl.)
• Now, a heaping spoonful at a time, add the yogurt or quark.
• Mix together.
• Then using a spatula, carefully fold in the Whipped Cream 1/3 at a time. Just fold it over and over on itself until you can't see streaks.
• Pour the cream mixture over the cake base in the pan.
• Top with the cake top.
• Cover with plastic wrap and refrigerate for at least 2 hours.
• (You can make it the day before)

Serving:

• When you are ready to serve, run a knife around the edge to loosen the cake from the pan. Remove the pan.
• Sprinkle with powdered sugar (the smallest packet)
• Serve.
• It's nice with some sliced strawberries.