A:「今(いま)買(か)ったケーキはどう?食(た)べてみたい。」
B:「ケーキおいしいのなんのって、もう完食(かんしょく)しちゃったほど。」
A: "How is the cake we bought today? I want to try."
B: "It was so delicious (to the point) that I ate it all already."
[When speaking about the past, のなんのって can be used with both non-past and past forms]