Mix flour and baking powder and put in a mixing bowl. Add sugar, lemon juice, milk, grated pistachios and egg and mix well for 2-3 minutes. Spread the dough 1 cm thick on a baking sheet lined with baking paper and bake in a preheated oven at 180 °C for about 35 minutes. Remove from baking sheet and cut into 1.5 x 4 cm pieces when completely cool. For the glaze, melt the coconut oil over mild heat. Stir in sugar, vanilla sugar, milk and cocoa until well blended. Dip each slice in the glaze and roll in coconut flakes and grated pumpkin seeds.