Combine the milk, yeast and sugar in a small bowl/jug. Cover the mixture and set aside in a warm place for 10 minutes or until frothy. Add the egg and whisk to combine.
Make the custard - combine the milk, custard powder and caster sugar together in a saucepan. Stir over a medium heat for 2-3 minutes until thickened. Set aside to cool completely
Place the flour and butter in the bowl of a food processor. Process until the mixture resembles fine breadcrumbs. Add in the yeast mixture and process until combined.
Transfer the dough to a lightly oiled bowl and cover with plastic wrap. Set aside in a warm, draught-free place for 45 minutes (until doubled in size).
Preheat the oven to 180 °C. Live a tray with baking paper.
Turn the dough onto a lightly floured surface and knead for 3-5 minutes, until smooth and elastic. Use a rolling pin to roll the dough into a 30 x 40 cm rectangle.
Combine the berries and extra sugar in a bowl. Spread the custard evenly over the dough. Spoon the berry mixture evenly over the ricotta.
Starting with the longest side closest to you, roll up firmly to form a log. Cut cross-ways into 10 even portions. Arrange the scrolls in a circle formation, with 9 scrolls surrounding a middle scroll. The scrolls should be side up, side by side and just touching on the lined tray.
Combine the egg yolk and milk in a small bowl. Brush the egg mixture over the scrolls. Bake in the oven for 20-25 minutes, or until golden.
Whisk together the icing sugar and lemon juice to make a thick paste. Drizzle over the top of the scrolls while still warm. Serve immediately.