With cookies, there is always plenty of taste and it's super convenient because you can eat them at any time of the day! This French sandwich cookie recipe will have you returning to your kitchen for more!
To make the cookies, mix together the flour, baking powder, bicarbonate of soda and1/2 tsp of salt. In a large bowl, beat together the butter, sugar and lemon zest for 5 minutes until light and fluffy. Whisk in the eggs, then briefly mix in the vanilla extract. Add the dry ingredients and the cranberries, and mix until a soft cookie dough is formed. Cover and chill for 2 hours or until firm.
Heat the oven to 180C/fan 160/gas 4.Cut the dough into golf-ball-sized pieces, roll into balls and put onto baking-paper-lined trays. Bake for 14-16 minutes or until lightly browned. Halfway through baking remove the trays from the oven and give them a firm tap on the surface to make the cookie collapse a little (this will give a chewier texture). Cool on the trays for 5 minutes before removing to a wire rack to cool completely.
For the buttercream, put the milk and pistachios in a pan over a medium heat and bring to a simmer. Remove from the heat, cover and leave to infuse for 1 hour. Pour the mixture into a jug and use a hand blender to purée until smooth (the nuts won’t fully break down but they’ll form a slightly pasty texture, almost like a milkshake). Pour the milk mixture back into the pan along with the flour, caster sugar and vanilla bean paste. Cook over a medium-high heat, whisking constantly, until the mixture is very thick, like a pastry cream. Scrape the custard into a small bowl and cover the surface. Chill for 2 hours.
To finish the buttercream, beat the butter until soft and creamy then add in the pistachio custard a spoonful or so at a time. Continue beating until a buttercream texture is formed. Depending on the color of the pistachios you use you may want to add a drop or two of green food coloring – but be sparing. Put the buttercream into a piping bag fitted with a round nozzle and pipe a dollop of buttercream onto1/2 the cookies, sandwiching together with a second cookie. To finish, roll each cookie in chopped pistachios, coating the exposed buttercream.
