Make the Gâteau Invisible: Peel the apples and remove the cores. Slice them very thinly.
2. Step
Preheat the oven to 350˚F (180˚C).
3. Step
In a medium bowl, whisk the eggs and sugar until pale. Add the milk and melted butter and mix well.
4. Step
Sift in the flour and combine. Add the sliced apples. Using a rubber spatula, coat the apples well with the batter.
5. Step
Spoon the apples into a parchment paper-lined loaf pan, then pour over the remaining batter. Top with sliced almonds.
6. Step
Bake for 40 minutes. Cover with a foil and bake another 10 minutes.
7. Step
Let cool, then remove the cake from the pan.
8. Step
Make the butter caramel sauce. In a microwave-safe bowl, add the sugar and butter. Microwave 2 minutes or until sugar turns dark brown. Using oven mitts, very carefully take the bowl from the microwave. The bowl and sugar will be extremely hot so be careful when you are handling them.
9. Step
Immediately add the cream and whisk well with a metal spoon or whisk (this will splatter a bit, but keep stirring!).