Combine flour, salt, sugar, ground almonds, whole almonds, and baking powder. Gently stir with wooden spoon to mix thoroughly.
Mix beaten egg, and almond extract
Make a well in flour mixture and add the diced butter
Rub in with your hands until the mixture resembles rough breadcrumbs
Add the beaten egg and almond mixture
Gently stir with wooden spoon till it starts to come together then thoroughly mix using hands
Use flour on your hands to clean them of any biscuit mixture and if mixture is too sticky, add a little flour at a time until you can form a ball
Roll the ball out into 2 logs around 1 inch wide
Place on a tray lined with greaseproof paper and place in a preheated oven at 170°C for 30 minutes
Remove and let log cool completely and lower the oven temperature to 150°C
Cut cooled log diagonally into individual biscuits, then place back in the oven for a further 30 minutes
Meanwhile melt the chocolate in a bowl over barely simmering water
Remove biscotti from oven after 30 minutes and let cool completely before drizzling with melted chocolate and allowing the chocolate to set before serving