In a large bowl, mix together the butter and sugar until it is creamy and light.
To the mixture add the vanilla and egg and combine well.
Add in the sourdough discard and combine.
Pour in the salt and flour to the bowl and combine. Make sure to not over-mix the ingredient – just until they are combined.
Once the dough is combine, consider putting it into the fridge for a few hours. This will help the cookies keep their shape while in the oven, but it is optional.
Now it is time to roll the dough out. Use a rolling pin to roll the dough to about ¼” thick.
Use cookie cutters to cut out the cookies in whatever shape you prefer.
Preheat the oven to 350 F / 180 C and line a baking tray with parchment
paper.
Put the cookies on the baking tray and put them into the oven for 10 minutes or until the edges are slightly golden.
Allow the cookies to cool completely before icing them.