Buttery marble cake

Well, here's my recipe for an extremely awesome buttery marble cake....being true to my punjabi self, who likes everything buttery, n not too sweet except for jalebis... i fixed this recipe:

Ingredients:
1. Flour - 2 cups
2. Baking powder 2+ 2/3 tsp
3. Salted butter - a lill more than 2 sticks of butter - 225 g
4. Eggs - lightly beaten -4
5. Sugar - 2/3 cup
6. Orange Juice - 1 teacup -I just used Tropicana - if you are using fresh orange juice then make the sugar 1 cup
6. cocoa powder - 3 tablespoon

Method:

Heat the oven to 190C
Beat together butter and sugar until light and creamy. Add eggs slowly n beat.
Add flour to the butter and eggs mixture and fold in.
Divide the batter into two parts.
Mix half orange juice with cocoa. Fold in one half of the batter to this.
To the second half of the batter add the orange juice.
Line the baking pan with baking paper or prepare the pan by greasing with a little butter.
Add the two batters to the pan in alternating spoons.
Once all the batter has been added, swirl the mix once.
Bake at 190C for 45 minutes or till a toothpick when inserted comes out clean.
Let the cake cool on a wire rack.
Slice and enjoy with a cup of tea/coffee, as you like it best ;-)