Preheat your oven to 350°F (175°C). In a large bowl, cream together softened butter and sugar until light and fluffy, about 2-3 minutes. Stir in the egg and vanilla, mixing well.

In a separate bowl, combine flour, baking powder, and salt, then gradually blend with the wet ingredients to form a soft dough. Press this dough into the bottom of a 9-inch springform pan and bake for 10-12 minutes until edges are lightly golden. Allow to cool slightly.

While the crust cools, prepare the cheesecake filling by beating softened cream cheese until smooth, about 3-4 minutes. Gradually add sugar and vanilla, blending well.

Incorporate eggs one at a time, ensuring each is fully mixed before adding the next. If using, mix in sour cream and a touch of flour until fully creamy and smooth.

Pour the cheesecake filling over the cooled crust, spreading it evenly. Tap the pan to release air bubbles.

Lower the oven temperature to 325°F (163°C) and bake for 40-50 minutes, until the cheesecake is set but slightly jiggly in the center.

After baking, turn off the oven and crack open the door to cool gradually for about 30 minutes. Transfer to counter to cool for another 10-15 minutes, then refrigerate for at least 3-4 hours or overnight.

Remove the cheesecake from the springform pan. Top with whipped cream, sugar sprinkles, and fresh berries. Slice into wedges and serve.