Preheat your oven to 180°C (350°F). Grease a 23 cm (9-inch) round cake pan and set aside. In a mixing bowl, beat softened butter and sugar until creamy and light. Add vanilla extract, then beat in eggs one at a time, ensuring each is well incorporated. This creates a smooth, rich batter that forms the foundation of your cake.

In a separate bowl, whisk together all-purpose flour and baking powder. Gradually add the dry ingredients to the wet mixture, folding gently. Alternately add yogurt, sour cream, or buttermilk to keep the batter moist and fluffy. Do not overmix—just fold until combined. Carefully fold in the black currants, distributing them evenly throughout the batter.

Pour the batter into the prepared cake pan. Smooth the top with a spatula. Bake for 40-45 minutes, or until a toothpick inserted into the center comes out clean. The cake should be golden and risen, with bubbles forming around the black currants.

Let the cake cool in the pan for about 15 minutes. Then transfer it to a wire rack to cool completely. This step allows the flavors to meld and the cake to set. For an extra touch, dust with powdered sugar or serve with fresh berries for a vibrant presentation.