Preheat oven to 180°C.
Sift the flour, bicarbonate of soda and salt together.
Cream the butter and sugar until very light in colour.
Add the eggs and peanut butter and mix through.
Lightly fold in the dry ingredients, cover and refrigerate for 30 minutes.
Drop spoonfuls of batter onto greased baking trays, leaving 25 mm space between biscuits.
Press dough down lightly with a fork to form a pattern on top.
Bake for 14 - 16 minutes or until golden brown.
Allow to cool for a few minutes on baking trays before transferring to the wire racks.
Allow to cool completely.