Pastry:Mix the egg yolk, water, and vanilla, and set aside.Mix the flour, sugar, ground peanuts, and salt in the bowl of a food processor, fitted with a steel blade.Add the butter and pulse until the mixture is coarse.Add the egg mixture and pulse until the dough comes together in a ball.Wrap in plastic wrap and refrigerate for about 30 minutes.Preheat the oven to 425F (220C).Roll out the pastry to a thickness of 1/8″ (0.3cm) on a floured surface.Line the tart pan with the pastry, brushing the edges with butter.Prick the bottom with a fork, cover with aluminum foil, and fill with dried beans.Bake for 5 minutes, then reduce the oven to 350F (180C).Remove the beans and foil and continue baking for 15-20 minutes, or until the pastry is golden brown.Transfer to a wire rack and let cool completely.Caramel:Heat the cream and set aside.In a saucepan, combine the sugar and corn syrup and cook until a amber caramel is obtained.Add the cream, being careful of splatters, and mix until smooth and homogeneous.Add the butter and mix well.Add the peanuts to the caramel, mix, and pour the mixture into the cooled tart shell.Refrigerate for 15 minutes.Ganache:In a bowl, melt the chocolate in pieces.Heat the cream until it boils, then pour it over the chocolate.Mix until smooth and homogeneous.Add the butter and mix well.Pour the mixture into the cooled tart shell.Refrigerate for 30 minutes.To serve, let it rest for a few minutes at room temperature.