In my mind, there are two types of plums. The first are those that appear year-round in supermarkets, often in plastic punnets with a label saying 'Ripen at home'. They are imported, usually from South Africa. They are often nearly perfectly spherical, firm and glossy-skinned, and come in three different colour varieties: bright greenish-yellow, slightly translucent; dark black-purple, with a matt white bloom misting the surface; or vivid uniform magenta. These are perfectly fine - they are very reliable, delivering without fail a pleasantly tart crunch when slightly underripe and something slightly more sweet when ready. They also cook well, holding their shape under the pressure of heat.

But far more interesting, I think, are those native plum varieties that appear in markets at this time of year. At any one time during the autumn months you can spy four or five different types at any one time, if you know where to look - find a good farmers' market or local greengrocer. For me, this experience presents itself a bit like a pick & mix sweet stall might to a child. There are round ones, oval ones, dimpled ones, smooth ones. There are blushing ones, bright ones, glossy ones, matt ones. There are shades of yellow, orange, russet, green purple and red to conjure up images of the autumn foliage to come. Some are hard and firm, others so quiveringly jelly-like that they have to be cosseted carefully in the bike basket home and still, inevitably, will end up squashed or punctured in places.

I came across a particularly beautiful crate of plums last weekend at Newgate Market in York. Despite having enough fruit to last me the week's breakfasts already, I couldn't resist taking home a bulging bag of these beauties. They are a beautiful golden yellow, mottled with a russet-red blush, delicately oblong in shape with a curve down the centre like a cleft chin. They spoke to me of everything good about autumn: of warm ovens, sugar, spice, citrus, the aroma of baking fruit.

I rarely, if ever, eat plums raw. Why would you, when baking them or poaching them concentrates their flavour to exquisite, sweet-tart perfection? I find their jelloid texture when very ripe a bit sickening, and some varieties can be disappointingly watery, but cooking them always delivers delicious and reliable results, and is very simple. Just include some sort of sweet element - honey, brown sugar and stem ginger syrup all work well - some type of spice, such as star anise, ginger, cloves or cinnamon, and a bit of citrus to bring out the tartness of the plums - orange is the best for this. You can poach or bake, depending on the result you want - poaching will give a softer texture and more syrupy juice, and the plums collapse quite easily if ripe. Baking helps keep their shape, and you get lovely little charred edges on the top of the fruit where it has been singed in the oven.

I was amazed by just how delicious my market treasure tasted, after I baked it in a little orange juice with some stem ginger in syrup scattered over, a little brown sugar and some cloves and star anise. I spooned the fruit, on the point of collapse (the fruit, not me), over a bowl of granola, drizzled over some of the juices from the cooking, and threw over some plump fresh raspberries. Alongside a cup (okay, three) of jasmine tea, this was one of the best autumn breakfasts I've ever had. And that's saying something, because I am a total domestic goddess when it comes to inventive and delicious breakfasts.

Naturally, I couldn't resist going back for a second haul of these magical plums. This time, however, I decided to turn them into something even more decadent by pairing their incredible sweet-sharp flavour with a decent amount of butter and sugar. Last year I adapted Dan Lepard's recipe for plum and cobnut crumble tart to make this apple, quince and almond tart. This year, I wanted to make the original plum variety. I don't bake enough with plums, I've decided - I only ever eat them on my breakfast - and I think they need to see more butter-sugar-flour action in my kitchen.

This is a very simple tart to make. You essentially make a crumble, enriched with hazelnuts (I couldn't get any cobnuts, sorry Dan), then use half of it to line a tart tin, pressed into the bottom and the sides. You mix plums with lemon juice, sugar and cornflour, spoon this in, then sprinkle the remaining crumble over the top. A crumble and a tart in one go - best of both worlds - and much less faff than rolling out proper pastry.

I made a few changes to the original recipe, because I'm incapable of not doing so. I used some spelt flour in the pastry, because I love its nutty flavour. I put salt in the pastry mix, because it helps to bring out the sweetness of the filling and makes everything that little bit more moreish. I added ground ginger and orange peel powder (from JustIngredients - this stuff is magical with any fruits you want to make spicy and autumnal and delicious) to the plum mixture, to give it a little more spicy depth of flavour. I sprinkled demerara sugar over the tart before baking, for more crunch. Oh and I also made a somewhat inadvertent change to the recipe by adding the baking powder to the plums and lemon juice by mistake rather than the crumble, in a fit of complete absent-mindedness and incorrect autopilot. Remember those chemistry experiments that involved adding alkalis and acids together to make a volcano? My plums were basically sitting in Mount Etna. Oops.

In case you are wondering, the tart will still be delicious, should you accidentally add the baking powder to the wrong component. This is everything you want from an autumnal dessert - it's crumbly, buttery and deliciously nutty from those wonderful toasted hazelnuts - no other nut gives out quite as much depth of flavour, I don't think. The crunchy crumble gives way to a vein of tart-sweet juicy plums, which have soaked into the surrounding crumb and made it moist and tangy and delicious. It's simple to make but still looks elegant and refined, and actually cuts into fairly neat slices if you leave it to cool first. It is superlatively excellent with a couple of scoops of vanilla ice cream, which sets off the buttery, crunchy crumble and juicy tart plums perfectly.

This takes everything I love about roasted plums, and combines it with crumble. So...er...it was obviously going to be great.

Plum and hazelnut crumble tart (serves 6):

Adapted from Dan Lepard's 'Short and Sweet'.

For the pastry:

100g cold butter, cubed
100g plain flour
80g spelt flour
50g light muscovado sugar
1/2 tsp baking powder
50g toasted hazelnuts, finely chopped
1 tbsp milk
1/2 tsp salt
1 tbsp demerara sugar

For the filling:

300g ripe plums, stoned and finely diced (weighed after stoning)
Juice of half a lemon
50g light muscovado sugar
1 tbsp cornflour
1/2 tsp ground ginger
1/2 tsp orange peel powder (optional)

First, make the pastry/crumble. Either blitz all the ingredients except the demerara sugar in a food processor, or rub the butter into the flour until the mixture resembles fine breadcrumbs, then stir in the other ingredients except the demerara sugar. Grease an 18cm loose-bottomed tart tin, then press half the mixture into the bottom and sides of the tin with your fingers to line it. Pre-heat the oven to 180C.

For the filling, mix together the plums, lemon juice, sugar, cornflour and spices in a small bowl. Spread this over the pastry in the tart tin, then sprinkle the remaining crumble mix evenly over the top. Sprinkle over the demerara sugar, then bake for around 50 minutes until the tart is golden brown.