Preheat your oven to 350°F (180°C). Grease a ring pan and dust with flour or fine breadcrumbs.

In a mixing bowl, cream the butter and sugar until fluffy. Mix in the vanilla.

Add the eggs one at a time, mixing well after each addition.

In another bowl, combine the flour, baking powder, and salt, then add the dry ingredients and milk alternately to the butter mixture, mixing just until combined.

Spoon the batter into the prepared ring pan, smoothing the top.

Bake for about 35 to 45 minutes, until a toothpick comes out clean. Cool for 10 minutes in the pan before turning out to cool completely.

In a saucepan, whisk the pudding powder (or cornstarch) with a little milk until smooth.

Heat the rest of the milk with sugar until warm, then whisk in the pudding mixture and cook until thick.

Cover the surface with plastic wrap and cool to room temperature.

Beat the softened butter until pale and creamy, then gradually add the cooled pudding until fully combined.

Slice the cooled cake horizontally into 2 or 3 layers.

Spread a thin layer of jam on the bottom layer, then spread buttercream filling.

Stack the layers and coat the outer sides with buttercream.

Press caramelized nuts onto the sides and top of the cake.

Pipe a few buttercream rosettes on top and add cherries if desired.