Oatmeal & Raisin Chocolate Cake

I came across this Oatmeal & Walnut Marble Cake recipe in My Wok Life blog and i was tempted to give it a try. But i make some changes to it in the recipe.

Ingredients (A):
100 ml of water
50 grams of quickcook or old-fashioned rolled oats (or instant oats)
1 tablespoon of condensed milk

Ingredients (B):
200 grams of hard butter, may cut into smaller chunks for easier creaming
90 grams of sugar
3 large eggs
170 grams of plain flour, sieved (I used Self Raising Flour and omit the baking powder)
2 teaspoons of baking powder
1 teaspoon of vanilla essence
50 grams of semi sweet baking chocolate bar, melted in a small pot over a pot of simmering water (Double-boiling Method) (I used cocoa powder)
Optional:
50 grams of walnut, coarsely crushed and toasted at 150C, for 5 minutes (I used raisin)

Utensil:
9" deep round or square baking tin, greased with olive oil or line baking sheet

Method:
1) Mix water, quick oats and condensed milk [Ingredients (A)] in a pot and boil over medium heat till gruey consistency, for 1 minute. Stir occasionally. Heat off and leave aside to cool. (**If using Old-fashioned rolled oats, heat 5 minutes longer. If using Instant oatmeal, omit this heating process. Simply add it into the cake mixture in Step 5.)

2) Preheat oven to 160C, for 20 - 30 minutes.

3) Cream hard butter and sugar in a mixing bowl at medium speed till fluffy, for 15 minutes.

In the meantime, melt chocolate bar with double boiling method listed above. Keep the melted chocolate in the hot water pot as it is, to keep it warm.

4) Reduce speed to low, mix in eggs slowly, in stages (one egg at a time). Add vanilla essence. Then, increase speed to medium again to mix well, for about 3 - 5 minutes.

5) Stop blending. Add in oat mixture, sifted flour and baking powder. Use a plastic spatula to combine well. **(May beat with mixer at low speed, but do not over beat it to avoid cake texture becoming too compact instead of spongy.)

6) Add in walnuts and stir to combine. Then, add in melted chocolate and scatter in the cake mixture with spatula, to create marble pattern.

7) Pour cake mixture into baking tin and place at middle rack in oven to bake for 40 minutes. Leave at rack to cool before removing from tin. Divide into 10 big slices or 16 small slices to serve.