First, peel the pears and cut into wedges. Sprinkle with lemon juice and set aside.
Melt the chocolate with the butter in a bowl in the steamer at 60 °C for 10 minutes.
Beat eggs with sugar and orange liqueur until foamy. Mix flour with baking powder and stir in. Finally stir in the slightly overcooled chocolate-butter mixture.
Grease a tart pan with butter and sprinkle with crumbs. Pour in the batter and top with the pear wedges. Cook in a steamer at 100 °C for 25-30 minutes.
Serve the pear and chocolate cake sprinkled with powdered sugar.