2 cups plain flour
1 1/2 teaspoons baking powder
1/2 teaspoon bicarbonate of soda
1 cup buttermilk
3/4 cup caster sugar
1/4 cup unsweetened apple sauce
1/4 cup reduced fat margarine spread, melted
1 large egg
1 large egg white
3/4 cup (about 1 medium) peeled and grated zucchini
1/2 cup chopped walnuts (optional)
FOR THE CRUMB MIXTURE
1/4 cup cocoa, sifted
1/4 cup caster sugar
8 teaspoons chilled reduced fat margarine spread
Preheat oven to 180C. Line a 20x10cm loaf tin with baking paper; spray with vegetable oil cooking spray. For crumb mixture, combine cocoa and sugar in a bowl. Rub in margarine until coarse crumbs form. Reserve 6 teaspoons.
Sift flour, baking powder and bicarbonate of soda into a mixing bowl. Mix buttermilk, sugar, apple sauce, margarine, egg and egg white in a bowl. Add egg mixture to flour mixture; stir gently, until combined. Stir in zucchini and walnuts.
Pour half the mixture into prepared tin. Sprinkle crumb mixture over. Pour remaining mixture on top; spread level. Top with reserved crumb mixture.
Bake until a bamboo skewer inserted in centre comes out clean, about 1 hour. Cool on rack.
COOK'S TIPS -Measure out 3/4 cup of peeled, grated zucchini, lightly packed into a measuring cup. Be sure to measure carefully or the bread could be too densely textured.
For an attractive slice, swirl crumb mixture in centre of tea-bread with a skewer, to spread it, before covering it with the remaining mixture and baking.