Soak the raisins in filtered water for 15 minutes or for 1 hour, depending on the dryness of the raisins. Then put in a colander and dry. Cut candied fruits into small neat cubes, if necessary. Rub the curd through a sieve into a saucepan in order to get rid of lumps and small grains and make it completely smooth. You can also mince the curd twice or blend. Soften the butter to room temperature. Grate sugar with yolks and softened butter thoroughly or whip with a mixer to a fluffy mass. Then add sour cream to the curd and whip. Put the butter mass and whip again. Add vanilla seeds to the curd mass and rub it through a sieve into a small pot. Put this pot on a large saucepan filled with low boiling water by one third. Warm the curd mass to the first bubbles, constantly stirring so that the mass does not exfoliate. Then remove the pan from the water-bath. Cool the curd mass and refrigerate for 1-2 hours so that it hardens a bit. Add raisins, candied fruits and lemon peel, and stir carefully. Cover the inside of the paskha tin with gauze, place the curd mass and put some tightening weight atop (a liter jar half full with water). Refrigerate for 3 days. Place the tin in a deep dish so that the liquid drains off. Before serving, remove the tin and gauze, put paskha on a festive dish and put in the very center of a bright Easter table.