Preheat oven to 160ºC. Butter an 23cm tin with removable base and set aside.
Place sugar and butter into the Thermomix bowl and mix 1 min/speed 3. Scrape down sides of bowl.
Add eggs, flour, salt, vanilla, baking powder and milk and mix 10 sec/speed 6.
Scrape down sides of bowl and mix 5 sec/speed 5 if needed, repeat.
Spread the batter into prepared tin and smooth surface with the back of a wet spoon.
Peel and quarter apples. Thinly slice each quarter and arrange on top of the cake as you wish.
Brush with warmed apricot jam and bake for 40-45 minutes or until risen and skewer comes out clean.
Sauce; place all ingredients into Thermomix bowl and cook 7 min/Varoma/speed 3/MC off/spatter guard, .Blend 5 sec/speed 6.
Brush onto the cake and repeat until it has all been absorbed.
Preferably serve warm with custard, whipped cream and or ice cream.