Mix the peanut butter, butter and sugar. Beat in the egg then baking powder and bicarb..
Stir in the flour, making sure it is well mixed in. Stir in the chopped chocolate, crushed pretzels and cranberries.
Roll walnut sized balls of dough and place well apart to allow for spreading on greased/lined baking trays.
Flatten slightly with the back of a fork then bake for 12 - 15 mins, flattening again with a spatula half way through.
If you wish to have soft set biscuits, bake for 10 - 12 mins and up to 15 mins for a crisp biscuit. They will continue to cook and set even after removing from the oven.
Leave to cool for about 5 mins on the baking tray, then transfer to a cooling rack to cool fully.
Notes
These biscuits will keep in an airtight container for 5 - 7 days.*If preferred, you can use plain flour, or omit the baking powder, and use self raising flour