250 grams softened butter
1 1/2 cups sugar
3 eggs
1 1/2 teaspoon vanilla essence
3 cups flour
...
1 1/2 teaspoon baking powder
1 1/2 teaspoon bicarb of soda
1/4 teaspoon salt
375 ml creme fraiche
STREUSEL
This is the easiest done in a food processor.
Mix:
1 cup brown sugar
3 heaped teaspoons flour
3 teaspoons melted butter
1 teaspoon cinnamon
100 grams chopped Hazelnuts (or walnuts, pecans)
Heat oven to 180 deg. C. Grease two small loaf tins. Mix butter, sugar, eggs and vanilla. Beat for 2 minutes. Mix in flour, baking powder, bicarb of soda and salt alternately with creme fraiche. Spread 1/2 of the batter (approx. 1 1/2 cups) into each pan. Sprinkle each wiith 1/4 of the streusel mix. Repeat. Bake for 1 hour.
If you prefer a more aesthetically pleasing shape choose a container of at least 3 liter capacity.