Servings: 14 oz yield (enough for one triple-layer cake)
Over medium heat, whisk together brown sugar, granulated sugar, heavy cream, butter, and apple.
Continually whisk for 5-7 minutes, it should thicken during this process.
Add vanilla, cinnamon, and sea salt - whisk for another 1-2 minutes.
Remove from heat. Let sit a few minutes.
Refrigerate until cool and slightly firm.
Brunoise, a precision cut which produces small cubes. Small is necessary considering the smoothness of slices when serving the cake. There is very little 'precision' in home baking...just do your best.