How to Make It
Preheat the oven to 350°. Put the bread slices on a large rimmed baking sheet and lightly toast for about 7 minutes.
In a food processor, finely grind 1/2 cup of the hazelnuts. Transfer to a bowl. Add the confectioners' sugar and butter and beat at medium-high speed until light and fluffy, about 3 minutes. Add the amaretto and vanilla and beat for 1 minute. Add the egg and beat until incorporated. Spread the hazelnut cream on the toasts.
Peel, halve and core the pears. Slice each pear half lengthwise 1/4 inch thick; spread them into fans. Brush with lemon juice. Using a spatula, transfer the pear fans to the toasts. Dust the pears with confectioners' sugar. Bake for about 30 minutes, or until the hazelnut cream is set and nicely browned. Dust the toasts with confectioners' sugar and scatter the remaining 1/4 cup of chopped hazelnuts over the top. Serve right away.