In a large bowl combine all-purpose flour, baking powder, pinch of sea salt and allspice. In another large bowl combine butter and sugar, using stand mixer or hand mixer. Mix for about 10 minutes. Add the egg, peanut butter and continue to mix until you get a nice mixture.TipYou can make peanut butter at home, by placing the peanuts into a blender / food processor. Process for about 5 minutes on high speed.
refrigerate the dough
Incorporate the flour mixture into the peanut butter mixture. Mix briefly. Shape the dough into a cylinder about 4 cm / 1.5 inch in diameter. Wrap the dough using a plastic foil. Refrigerate for 30 minutes. Meanwhile, preheat the oven to 180°C / 355°F.
Slice the chilled cylinder into 1,5cm / 0.5 inch thick slices. Place them in line on a baking tray, lined with parchment paper about 2 inches apart. Bake for 10 - 12 minutes or until the edges become golden brown. Remove from the oven and transfer the peanut butter cookies to a cooling rack to cool.
In a small saucepan bring the heavy cream to a boil. Place caster sugar in a dry pan. Heat over the high heat to dissolve the sugar. Let the mixture dissolve completely. Remove from the heat. Slowly add the hot heavy cream, stirring constantly, as fast as you can. Be careful not to create lumps. Add the sea salt and white chocolate. Continue to stir until the white chocolate melts and is well incorporated into a caramel.
Dip the cookies halfway into the caramel and place them on parchment paper to set. Sprinkle with fleur de sel. Serve warm, or store in a sealed container for up to 10 days.