In a mixer or large bowl, mix together the flour, sugar, yeast and salt, then add the milk and 3 of the eggs and continue mixing to make a smooth dough - 5 mins in the mixer or 8 mins by hand. Add the softened butter and mix for a further 5 mins in a mixer or 10 mins by hand. Put the dough in a lightly oiled bowl and leave in the fridge overnight. Your dough will then be stiff and easy to shape.
Grease 2 x 500g bread tins, then divide the dough into about 16 pieces and prod some apricots into each piece. Seal them up and shape into little balls. Place the balls in a tin in sequences of 2 until the tin is full. It should take no more than 8 pieces to fill each tin. Leave the brioche for 3 hrs to prove until doubled in size.
Heat oven to 200C/fan 180C/gas 6. Brush with 1 beaten egg and bake for 20 mins until golden brown and the loaves sound hollow when tapped underneath. Cool on a wire rack.