Grease 4 (8-inch) cake pans and line with parchment paper. Preheat the oven to 180°c.
Cream the butter and sugar together in a mixer on medium-high speed and beat for 3 minutes or until light and fluffy. Beat the eggs in, one at a time, scraping down the sides of the bowl after each addition. Beat in the vanilla.
In another mixing bowl, combine the Schär Gluten Free Flour with the baking powder.
Turn the mixer to low, add half the flour mixture to the butter/egg mixture, then the milk, and finally the rest of the flour mixture. Beat until fully combined. Using a rubber spatula, scrape the sides and bottom of the mixing bowl and make sure the batter is fully mixed. Divide the batter evenly among the 4 prepared cake pans. Bake for 25-30 minutes or until a toothpick inserted into the center comes out clean. Let cool in pans for 10 minutes then transfer to a wire rack to finish cooling.
If the cakes are domed, slice off the dome so you have flat layers. Place one layer on a cake stand, spread on about 60ml of apricot jam, top with another layer of cake and repeat, ending with a cake layer with no jam on it.
Frost the cake generously with chocolate frosting. Surround the cake with twin bars, pressing firmly into the frosting. If desired, tie a ribbon around the middle and decorate with edible Autumn leaves.
