Get your tin ready. Preheat your oven to 175°C (155°C fan, gas mark 4) and line a 12-hole muffin tin with cupcake cases.
Mix the dry ingredients. In a bowl, whisk together the 155 grams plain flour 1 ½ teaspoon baking powder, ¼ teaspoon bicarbonate of soda and ¼ teaspoon salt, then set aside.
Cream the 113 grams unsalted butter and 150 grams caster sugar. Beat the softened butter and sugar together for 3 to 4 minutes, until it's very pale and fluffy. It really is worth taking your time with this step.
Add the eggs. Add the 2 large eggs one at a time, beating well after each one, then mix in the 2 teaspoon vanilla extract.
Combine the wet ingredients. In a separate bowl or jug, stir together the 120 grams sour cream and 60 mililitres whole milk.
Bring the batter together. Add the dry ingredients to the butter mixture in three additions, alternating with the sour cream mixture. Mix only until everything is just combined.
Fill the cases. Divide the batter between the cupcake cases, filling each one about two-thirds full.
Bake. Bake for 18 to 21 minutes, until the tops spring back when you lightly touch them.
Cool completely. Let the cupcakes cool fully before you fill them. Warm cupcakes will make the filling and ganache melt and slide about.
Start the cherry filling. Add the 300 grams pitted cherries, 67 grams caster sugar and 1 tablespoon lemon juice to a saucepan over a medium heat. Cook for 5 to 7 minutes, stirring now and then, until the cherries soften and release their juices.
Thicken it. Mix the 1 tablespoon cornflour and 1 tablespoon cold water together to make a slurry, then stir it into the cherries. Cook for another 1 to 2 minutes, until the filling is very thick.
Finish and cool the filling. Take the pan off the heat and stir in the 1 teaspoon vanilla extract and ⅛ teaspoon almond extract, if using. Leave it to cool completely.
Melt the white chocolate. Place the finely chopped 170 grams white chocolate in a heatproof bowl. Heat 120 grams double cream in a small pan until it's steaming but not boiling, then pour it over the chocolate and leave it to sit for 2 minutes.
Make the ganache base. Stir slowly until the mixture is completely smooth, then stir in the 1 teaspoon vanilla extract and Pinch of salt.
Add the cold cream. Whisk in the remaining 240 grams cold double cream until combined.
Chill. Cover the bowl and pop it in the fridge for at least 4 hours, or overnight if you can.
Whip the ganache. Once it's thoroughly chilled, whip it with a mixer until it's light, fluffy and holds its shape well enough to pipe.
Core the cupcakes. Use a cupcake corer or a small knife to remove a small hole from the centre of each cooled cupcake.
Fill them. Fill each cupcake generously with the cooled cherry filling.
Pipe the ganache. Pipe the whipped white chocolate ganache high on top of each cupcake.
Add the finishing touches. Top each one with a cherry, some white chocolate curls or shavings, a tiny drizzle of cherry sauce, and a light dusting of icing sugar if you like.