Coffee cake

As we need to empty the cupboards because we are going on holidays, I wanted to try a coffee cake. I didn't have enough to do a sponge cake so I looked on the Internet for the recipe of a normal cake. 

Ingredients:
For the cake
-75g butter or margarine
-75g sugar
-2 eggs
-75g self-raising flour
-1/2 and 1/4 teaspoon baking powder
-1 tablespoon boiling water
-1 tablespoon coffee granulates

For the filling:
-200ml double cream
-2 tablespoon icing sugar
-1 teaspoon coffee granules for 2 tablespoons boiling water

• Preheat the oven to 180°C/Gas 4. Grease your tin.
• Beat butter and sugar until pale and creamy. This will take only a few seconds.
• Lightly whisk the eggs in a mug. Gradually add them to the mixture. Add flour a tablespoon at a time whilst beating. Beat in baking powder.
• Dissolve the coffee granules in boiling water and fold it gently. 
• Pour the mixture in the tin and bake for 30 minutes and let it cool for 5 to 10 minutes. 

• For the filling, add all the ingredients in a bowl and whisk until the cream forms soft peaks. 
• With a piping bag or a spatula spread the filling on the cake and done!