Preheat the oven to 350 and grease 1/2 sheet pan or 2 9 inch round cake pans (for the rounds also line the bottom with parchment to prevent sticking!).

Combine all of the dry ingredients in one bowl and all of the wet ingredients in another bowl (to get all of the chestnut puree incorporated into the wet ingredients I often use a immersion blender or hand mixer). Whisk the wet ingredients into the dry ingredients (don't over mix, stir just until there's no flour clumps). Pour into the sheet pan and bake until golden brown and a toothpick comes out clean (about 22 minutes for a sheet cake). Let cool the top with dulce de leche cream.

In a stand mixer whip together the whipped cream with 1/3 cup of dulce de leche until soft peaks form. Use a spatula to spread this over the top of the cake. Warm the other 1/4 cup or dulce de leche up (about 25 seconds in the microwave) then use a fork to drizzle it over the top of the whipped cream.

For a double layer round cake, invert the two cakes onto a wire rack ounce cooled and remove parchment from the bottom. Place one layer on a large plate or cake plate then top with half of the whipped cream and half of the warm dulce de leche. Place the second layer on top then top with remaining whipped cream and dulce de leche.