Place the white chocolate and the butter in a microwave-safe bowl and heat on 50% powder in 15-second intervals, stirring after each interval, until chocolate is melted and mixture is smooth. Combine the remaining ingredients in a large mixing bowl and beat with an electric mixer set to medium for 2 minutes. Beat in the white chocolate until combined. Divide batter evenly between prepared cake pans and smooth with a spatula.
If your cake layers are too concave for your liking, chill the cake layers, then even them out with a long serrated knife.
Place one cake layer on a cake stand or cardboard cake circle. Spread half of the raspberry filling over the top of the cake (don’t go all the way to the edge). Gently spread (or pipe) a layer of frosting over the top of the filling, this time going all the way to the edge. Repeat with remaining filling and another layer of frosting. Top with remaining cake layer.
*I used Duncan Hines
**You can substitute cheesecake or vanilla pudding--just be sure that it's instant.