For the smoothest filling, be sure the cream cheese and eggs are at room temperature before mixing so they blend easily without lumps. Avoid overmixing once the eggs are added to minimize air bubbles, which can cause cracks as the bars bake and cool. If using frozen raspberries, thaw them fully and drain off excess liquid so the topping does not water down the cheesecake layer. Taste the raspberry mixture and filling before baking and adjust sweetness slightly if needed since different keto sweeteners vary in sweetness and aftertaste. For very clean slices, chill the bars overnight and use a thin, sharp knife, wiping the blade with a warm damp towel between cuts.