In full mad-scientist mode, I worked on this recipe for years. Now it's all grown up: time to set it free.

I can't even pretend to be modest about this: refined over years, this is an awesome recipe. It took hundreds of biscuits to get to this point – can I get some sad violins, please? – and now it's time to set it free.

Baking is the kitchen's exact science and, in true mad-scientist mode, I have tinkered with every element until these biscuits achieved the right combination of sweetness, saltiness, crispness and chewiness. My starting point is natural peanut butter, the kind that's made from nothing but peanuts. Sometimes you run cross a DIY machine in health food shops that you scoop peanuts into and peanut butter, somewhat magically, comes out. I use it because I can control both the sugar and salt, which isn't possible with the supermarket stuff in jars.

These biscuits, as perfectly good as they are by themselves, make the best ice cream sandwiches. Slap a scoop of really good vanilla ice cream between two of them and we’re rapidly approaching dessert nirvana.

So, you have choices. This recipe will make 30 biscuits; whether you want to make all 30 in one hit is up to you. They keep very well for at least a week in an airtight container (I don’t know if they keep longer because it’s never happened). You can also divide the dough and freeze what you don’t use. I suggest freezing it in balls – that way, they can go straight from freezer to oven with an extra 5 minutes cooking time. Instant biscuits? Yes, please.

Salted peanut butter biscuits

Makes 30.

130g (5 oz) natural peanut butter
110g (4 oz) soft unsalted butter
150g (6 oz) plain flour
½ teaspoon bicarbonate of soda
1 teaspoon coarse sea salt (or ½ teaspoon table salt), plus some for sprinkling
1 egg
100g (4 oz) sugar (ordinary white sugar)
100g (4 oz) light muscovado sugar

In the bowl of a mixer, beat the butter and peanut butter together until smooth. Add the sugars and salt, mixing until well combined, then beat in the egg.

Sift the flour and baking soda together (or simply stir them together with a balloon whisk in a big bowl), and add to the mixer with the beater running, a heaped spoonful at a time, until just combined.

Lay out a large piece of cling film on the bench and spatula the dough out of the mixer bowl onto the plastic. Wrap and put in the fridge for a least an hour. (It will survive quite happily for up to three days.)

When ready to bake, set your oven to 150°C (300°F).

Pinch off pieces of the dough, about 2 tablespoons, and roll with your hands into balls. The biscuits will spread, so space the balls about 10cm (4 inches) apart on a baking sheet. Flatten slightly with a wet fork in two directions to create a criss-cross pattern, sprinkle some sea salt flakes over and refrigerate on the tray for 15 minutes, which helps stop them spreading too much. I find it easier to work with two trays: one in the fridge, one in the oven.

Bake for 15 minutes, then allow to cool for 5 minutes on the tray before removing to a rack to cool completely.