Moist Apple & Walnut Crumble Cake

This is gluten free & delicious.

for crumble
3/4 cup roughly chopped walnuts
2 tbsp brown sugar
1/2 tsp groung cinnamon
for cake
1 cooking apple (approx. 170g)
125g unsalted butter, softened
1/3 cup caster sugar
2 eggs
3/4 cup gluten free self raising flour
1/4 cup buckwheat flour
1/4 cup maize cornflour
1/2 tsp ground cinnamon
1 tsp gluten free baking powder
1/2 cup milk (approx.)
1 tbsp brandy (optional)

Preheat oven to 170°C (150°C fan-forced).
Grease 11cm x 21cm loaf tin or 20cm round springform tin & line base with baking paper.
Process crumble ingredients & set aside.
Peel, core & grate apple & set aside.
Cream butter & sugar in small bowl of electric mixer until pale & thick.
Add eggs one at a time.
Scrape down sides of bowl.
Sift flours, cinnamon & baking powder together.
Add to creamed mixture with about 1/4 cup milk.
Do not over-beat.
Fold in apple & brandy, if desired.
Add remainder of milk only if batter is too stiff.
Spoon half batter into tin & sprinkle with half crumble.
Spoon in remaining batter & sprinkle with remainder of crumble.
Bake for 30-40 min or until cooked when tested with skewer.
Cool in tin for 5 min before turning out onto wire rack.