Consequently, it was too late when I realised that I made few mistakes! Anyway, I had no choice but let it go.. Fortunately, all mistakes made were not serious and I managed to get away with it... :)
As for the outcome, it smelled soooo nice ..I just had a small bite of the cake and it tasted good..buttery like Nicole said but not sweet as it should be because I reduced a lot of sugar in both of the cake and topping ! Can't think more about it right now..what I need to do is to eat a much bigger portion so that I could tell you more....what an good excuse !! lol..
Here is my version ( adapted from the original recipe )
2 cups all purpose flour
2/3 cup old-fashioned rolled oats
2 tsp baking powder
1/2 tsp salt
3/4 scant cup caster sugar
1/2 cup butter, room temperature
2 large eggs
1 cup buttermilk
1 tsp vanilla extract
1/2 rounded cup plain flour
1/2 cup brown sugar
100 g butter
1/2 tsp ground cinnamon
2/3 cup raisins
1/3 cup toasted walnuts, coarsely chopped
demerara sugar to spirnkle on top
Preheat the oven to 350F. Lightly butter 8'' square cake tin and line with parchment paper. Make the topping, combine flour, brown sugar, cinnamon, nuts and raisins in a medium mixing bowl and stir well. Rub butter into the mixture with your fingertips until mixture resembles coarse sand. Set aside.
Make the cake, in a medium mixing bowl, whisk together the flour, oat, baking powder and salt. In a large mixing bowl, cream together butter and sugar until light. Beat in eggs one at a time. Blend in 1/3 of the flour mixture, followed by half of the buttermilk and the vanilla. Then, blend in add half of the remaining flour, the rest of the buttermilk, and finally the last of the flour.
Pour half of the batter into the prepared tin. Top with half of the topping mixture. Pour remaining batter on top and spread carefully to the sides of the pan. Sprinkle all remaining topping over the batter. Bake for 40-45 minutes, or until a toothpick inserted into the center comes out clean. Allow cake to cool on a wire rack until it is room temperature before removing from the tin by lifting the parchment paper. Slice into pieces/ bars before serving.