Start by baking or purchasing a lemon poppyseed pound cake. If baking, you can enhance the flavor by adding lemon zest and poppy seeds. Allow the cake to cool completely before using it in the dessert.
Slice the cake thinly so it can be layered evenly in the pan. Thin slices are easier to cut later and help create a smooth base.
Wrap the outside of the springform pan with foil to prevent any leakage during freezing. Slice the cake and place half of the slices on the bottom of the pan.
Press the slices together gently so they form a uniform layer. This will become the sturdy base of the ice cream cake.
In a microwave-safe bowl, combine the white chocolate chips and whipping cream. Heat in short intervals until the mixture melts and becomes smooth when whisked together.
Pour half of the ganache over the cake layer but stop just short of the edges. Place the pan in the freezer for about an hour until the layer firms up.
Take the vanilla ice cream out of the freezer and allow it to soften slightly. Once it’s easy to stir, fold in the lemon curd gently so that streaks of curd remain visible.
Spread the ice cream mixture evenly over the chilled cake and ganache layer. Return the pan to the freezer for at least two hours so the filling sets properly.
Once the ice cream layer is firm, place the remaining slices of lemon poppyseed cake over the top. This creates the final cake layer of the dessert.
Press lightly so the slices sit evenly across the ice cream.
Warm the remaining white chocolate ganache slightly so it becomes pourable again. Spread it evenly over the top cake layer.
Return the entire cake to the freezer for at least six hours or overnight so it becomes fully set.
If desired, mix a little vanilla ice cream with whipped topping and pipe decorative borders around the cake.
Before serving, run a knife around the inside edge of the pan to release the cake. Slice with a knife dipped in hot water for clean cuts.