Mix in a bowl the butter and the sugar.
Next, you can add the ricotta cheese and mix it well with the butter and sugar, you will soften the cheese whisking it with a fork or with your whisk.
Add the eggs and mix again.
Now you can incorporate the flour, salt and baking powder and mix all the ingredients together.
Using a spatula you can add the chocolate chips, orange zest and a rum teaspoon to your cake batter.
Preheat your oven 180º Celsius (360º Fahrenheit).
Grease your cake pan or prepare it with baking paper and place the cake batter into the mold.
Bake for 40-50 minutes, it will depends on your oven, until you can prink with a knife and it comes out clean. Be careful not to burn the upper part, you can cover it.