Pre-heat your oven to 160C Fan/180C/350F/Gas Mark, and grease and line three 8 inch sandwich tins (that are at least 2" deep)
To make the sponge cream together the butter and sugar until light and fluffy. ideally using an electric mixer
Add the eggs two or three at a time and whisk them in
Then whisk in the self raising flour, cinnamon and apples
Divide the mixture between the three sandwich tins, I like to weigh it out for accuracy so the layers are even
Bake them for around 35-40 minutes, or until a skewer inserted in the middle comes out clean. Then remove them from the tins carefully and let them cool completely on a cooling rack
To make the buttercream, mix together the butter and icing sugar, ideally using an electric mixer
When it starts to come together add the cinnamon, milk and vanilla, and whisk until smooth. You can add more milk if it is too stiff
Stack the sponges up on your plate or cake stand, piping buttercream between each layer and drizzling salted caramel sauce over the buttercream, letting it drip down the sides of the cake
When you get to the last layer, use a spatula to spread a little buttercream in the centre reaching almost to the edge but not quite, then pipe rosettes all around the edge
Add the chopped pecans in the centre, then drizzle over more salted caramel sauce
Serve immediately, store leftovers in an airtight container in a cool place and eat within 3 days