For the dough, whip butter until fluffy. Add Egg, 3 tablespoons of water, sugar and vanilla sugar and blend until smooth. Stir in flour and baking powder. Knead into a smooth dough, wrapped in plastic wrap and chill for 30 minutes.
For the filling, mix together poppy seeds, 120 ml (approximately 1/2 cup) water, honey, sugar and salt and bring to a boil while stirring. Simmer for about 5 minutes and let cool. Stir in almonds, lemon juice and zest.
Roll out dough on a floured work surface and cut out thin circles about 8 cm (approximately 3 inches) in diameter. Place a small dab of filling in the middle of each. Sprinkle dough with water and fold into triangles, pressing edges around filling together.
Place on a lined baking tray and brush with egg yolk. Bake in preheated oven at 180°C (approximately 350°F) convection for approximately 20 minuntes until golden brown. Cool on a wire rack and serve as desired with figs.