Preheat oven at 180C/ 365F.
In blender add eggs, vegetable oil, sugar, milk and vanilla. Blend together for 2 minutes or until light eggs color.
In a large bowl, sift flour, baking powder, baking soda and salt together.
Pour the blended liquid to the dried ingredients.
Whisk all together until smooth cake batter.
Pour the cake batter in a 10 x 8 inch cake mold covered with parchment paper.
Bake for 25 to 30 minutes, test cake with insert a toothpick in the middle, if it comes out clean, then the cake is done.
Cool cake before spread the cream cheese mixture.
Melt instant coffee in 1/2 cup of hot water.
Poke a cake with a fork or a toothpick, soake with coffee.
In medium bowl, mix the mascarpone cheese with powdered sugar and heavy cream until smooth and creamy mixture.
Spread cheese mixture at the top of the cake and smooth with spatula.
Sprinkle cocoa powder with a small sifter until covered all the top.
Cover cake with plastic wrap and chill for 4 hours.
Cut into 9 squares and serve it.