Begin by preheating your oven to 350°F (175°C). For the crust, combine the melted butter, granulated sugar, flour, baking powder, and a pinch of salt in a bowl. Mix until a soft dough forms. Press this mixture into the bottom of a greased 9-inch (23cm) springform pan, ensuring it's even and compact. I learned the hard way that an uneven crust can lead to an unevenly cooked cheesecake, so take your time with this step.

For the filling, the key is to have your ingredients at room temperature. Beat the farmer's cheese in a large bowl until smooth. In a separate bowl, cream together the butter and sugar until light and fluffy. This process, known as creaming, is crucial as it incorporates air into the batter, giving the cheesecake a lighter texture.

Gradually add the eggs to the butter and sugar mixture, one at a time, beating well after each addition. I once added them all at once and ended up with a lumpy batter, a mistake I'll never make again. Patience here ensures a silky-smooth filling.

Blend the egg mixture into the farmer's cheese, then stir in the sour cream, flour, vanilla extract, and lemon zest. If you're using raisins, now's the time to fold them in gently. The zest and vanilla are more than just flavor enhancers; they're the subtle undertones that give this cheesecake its distinctive character.

Pour the filling over the crust in the springform pan. Tap the pan gently on the counter to release any air bubbles — a trick I learned after noticing unsightly holes in my first few attempts.

Bake in the preheated oven for 50-60 minutes. The cheesecake should be set around the edges but still slightly wobbly in the center. A common mistake is to overbake, which I did once, resulting in a dry, cracked top. Remember, the cheesecake will continue to set as it cools.

Turn off the oven and crack the door open, letting the cheesecake cool inside for an hour. This gradual cooling helps prevent cracking, a tip passed down from my grandmother that has saved many a cheesecake.

Once cooled, remove the cheesecake from the oven and chill in the refrigerator for at least 4 hours, preferably overnight. The chilling time not only solidifies the cheesecake but also deepens the flavors, making the wait worthwhile.

Before serving, dust the top with powdered sugar for a festive touch. I've always been apprehensive about using too much, but a light dusting adds a hint of sweetness and a snow-like appearance perfect for Christmas.