Preheat oven to 180 C (355 F) and line a baking tray with baking paper.
Put flour and butter together in a mixing bowl and use your fingers to rub butter into the flour. Once it is all combined, the mixture will resemble fine breadcrumbs.
Add peanut butter and mash it into the flour and butter to combine. Mix until dough is well combined and smooth.
Lightly flour a clean surface and a rolling pin.
Place dough onto floured surface and roll it out flat until it's 1/2 - 1 cm thick.
Use a cookie cutter (mine was about 6cm across) to cut out the biscuits from the dough.
Place biscuits, evenly spaced, onto prepared baking tray.
Bake in the oven for about 12 minutes.
Remove from oven and allow to cool completely.
Makes about 16 (may vary, depending on the size of your cookie cutter)