Viennese Pastry

Name: Viennese Pastry
Prep time: 20 min
Cook time: 30 min
Total time: 50 min
Cuisine: European, British
Ingredients: butter - 4/5 cup (200 g); powdered sugar - 4/5 cup (200 g); walnuts - 4/5 cup (200 g), chopped; flour - 1 cup (250 g); eggs - 2 small or 1 large; cocoa - 4 tablespoons, if desired; cinnamon - 2 tsp; cloves - 2 tsp ground; jam - 1 jar (apricot, plum or optional); lemons - zest of 1/2 fruit; rum - 1 tablespoon; hazelnuts - to decorate, can use almonds