Pre-heat oven at 180°, Line a 20cm spring form tin with baking paper side and base.add plain flour, sugar, baking powder and pinch salt.Mix with MC on, 20sec/speed4Add 80g of cold butter and turbo 2.0 x 2Add eggturbo 2.0 x 2Scrape down side and repeat turbo 2.0 x 2Add approx 2/3 of crumbly mixture into the cake tin and lightly press on the crumble to firm up slightly.Spead the Jam evenly and on top sprinkle with remaining crumble mixture.scatter on top the remaining 50g more cold butter. ( making sure your butter are smaller pieces and evenly scattered.Bake 30-40 minutes.Allow you jam crumble cake to cool and serve with vanilla ice cream.