Preheat the oven to 180 degrees Celsius, grease a pan with butter, and sprinkle sugar on the bottom and sides, removing any excess.

Cut the pears and remove the cores. Dice one pear into small cubes, placing them in a bowl on the side; this pear will go into the cake batter. Thinly slice the remaining two pears, and set them aside.

In a mixer bowl, whip chestnuts, vanilla, Fleur-de-sel and 150g of light brown/muscovado sugar. Begin at a slow speed until the chestnuts break into coarse chunks, then increase to medium speed until a crumbly texture with small chestnuts pieces is formed.

Add the soft butter to the mixer and continue to beat at medium-high speed until a light and airy mixture is obtained.

Gradually add eggs until a bright and smooth mixture is achieved.

In a medium bowl, mix the dry ingredients: flour and baking powder.

Add the dry ingredients and the crème fraîche alternately to the mixer bowl, mixing as little as possible, just until the flour is incorporated into the mixture.

Add the brandy and mix gently.

Using a spatula, fold the diced pear into the mixture. Fold gently to avoid crushing the pear.

Pour the batter into the pan and smooth the surface.

Arrange the two sliced pears on top of the cake in the desired pattern and sprinkle 25 grams of sugar over them.

Bake for 50-60 minutes until the edges and the surface of the cake turn golden brown. Cool to room temperature in the pan.

Once the cake is cool, remove it from the pan and serve.