In a bowl, using an electric mixer, combine the butter and chestnut spread.
Add the egg and mix until smooth.
In a small bowl, combine flour, baking soda and salt.
Add dry ingredients to liquid ingredients and mix.
Add half of the white chocolate and half of the pecans.
Preheat oven to 180º C (350º F).
On two cookie sheets covered with parchment paper, place the preparation which should give about 20 cookies, making sure to leave about 4 cm (1 ½ inches) between each.
Spread the remaining white chocolate and pecans on cookies, pressing lightly to push them in a bit.
Bake on middle oven rack for 9 to 10 minutes or, 1 to 2 minutes more to get a harder texture.
Remove from oven and let stand 2 minutes on cookie sheet before cooling on a rack.