Preheat your oven to 210 degrees and line a baking tray with baking paper.
Place the flour, butter and salt into the Thermomix bowl and mix for 10 seconds on speed 9 until mixture is the same consistency as bread crumbs.
Add the milk and mix for 7 seconds on speed 4 to combine.
Use the kneading function to knead the dough for 2 minutes.
Turn the dough out onto a floured bench and using a rolling pin, roll the dough out until you have a 30cm x 40cm rectangle.
Spread the softened butter all over the dough, leaving a 2cm gap around the edges.
Combine the caster sugar and cinnamon before sprinkling over the top of the butter and add the blueberries.
Starting at the long side, carefully roll the dough until enclosed and place in the fridge for 20 minutes to chill.
Cut into 12 slices which are approximately 2cm thick.
Place the blueberry scrolls onto a baking tray and make sure to leave enough room for the scrolls to rise.
Bake in oven for 20 minutes or until golden brown on top and cooked through.
Let the scrolls cool on the tray for five minutes while you make the Vanilla Icing by combining the icing sugar, boiling water and vanilla extract.
Pour the Vanilla icing over the top of the Blueberry Scrolls before letting them cool for a further five minutes.