Break the white chocolate into small pieces and place in a heatproof bowl. Create a bain marie by resting the bowl over a pan containing a small amount of water, ensuring the base of the bowl doesn't touch the water. Place the bain marie over a medium heat on the hob. Allow the chocolate to melt, stirring it regularly with a spatula. Remove from the heat once it has almost melted, the residual heat with continue melting any very small pieces of solid chocolate. Set aside to cool for 4 or 5 minutes.

Tip the mascarpone into a bowl. Use a metal spoon to briefly stir it to soften, avoid over stirring. Pour in the cooled melted white chocolate. Mix the mascarpone mixture well. Cover and place in the fridge to firm up for about two hours.

Peel, core and chop the pears. Place into a good sized pan. Add the cleaned blackberries (reserving 8 for decoration), sugar and water. Set the pan on the hob over a medium heat. Stir regularly allowing the sugar to dissolve as the mixture heats through. Add the lemon juice. Stir through. Continue to cook the jam remembering to stir it regularly.

Once the jam starts to reduce and thicken slightly remove 2 or 3 tablespoon of liquid to use as a coulis for the decorated cupcakes (place in a bowl and set aside).

Place a tea plate into the fridge, once cold spoon a small amount of hot jam onto the plate. Place back into the fridge for a couple of minutes and turn off the heat under the pan. Remove the plate from the fridge and gently run your little finger along the plate until it touches the jam. If the jam wrinkles it is ready. Decant into a clean bowl and set aside to cool. If it's not ready boil for a couple more minutes and retest in the same way.

Preheat the oven to 190℃ (170℃ fan)/375°F/gas mark Place the muffin sized cases into the muffin tray.

Place the soft butter and sugar into a good sized bowl and beat together with a wooden spoon or electric beaters until very pale and fluffy. Add the salt and vanilla extract and beat again to combine.

Gradually add the beaten egg a little at a time, beating well after each addition, (see note b below). Sieve the flour into the mixture. Use a spatula, large metal spoon to fold this into the batter with 1 tablespoon of milk. Ensure you have a nice dropping consistency. Add a little more milk if necessary.

Using a spoon, fill the cases with the batter mixture. You're aiming for them to be half to two-thirds full. Place the muffin tray in the centre of the oven and bake for 20 - 23 minutes. You may need to rotate the tray after 15 minutes of baking. Once baked, remove from the oven and muffin tray and place onto a cooling rack.

Once the cupcakes and jam have completely cooled begin to decorate them. Use a small paring knife to cut a cone from the top of each cupcake. (Alternatively use the wide end of a large metal piping nozzle and twist to remove a plug of sponge.) Use the tines of a fork to gently remove a little more sponge if necessary. Add one or two teaspoons of blackberry & pear jam mixture. Avoid over filling.

Fit a large star nozzle to a piping bag. Half fill the bag with frosting. Pipe a swirl of frosting on top of the cupcakes. (You will need to refill the piping bag at some point). Complete the cupcakes by placing one of the reserved blackberries on top of the frosting and drizzling a little of the reserved coulis over the top. Enjoy!