Preheat the oven to 350 degrees Fahrenheit. Grease a 12×6-inch loaf pan.

In a bowl of a standing mixer fitted with the paddle attachment, cream the sugars and the margarine until light and fluffy, about five minutes, scraping down the sides halfway through to ensure even mixing.

Add the eggs one at a time, while mixing.

Add the flour, salt, and baking powder and mix until fully incorporated.

Transfer batter to the pan. Bake for 45–50 minutes until an inserted toothpick comes out clean.

Cool completely before transferring to a cooling rack.

Bring mango, sugar, and water to a boil in a small saucepan. Lower the heat and allow to simmer for five minutes until mixture thickens and most of the water evaporates. Cool and blend with an immersion blender.

Beat whip until stiff peaks form. Add the vanilla pudding and beat.

Add whip to cooled fruit and whisk until combined. Do not overmix.

Combine all the ingredients in a small bowl. Mix until smooth.

Slice cake in half across the length, twice if desired.

Line a loaf pan with plastic wrap with some overhang.

Place one layer of cake into the loaf pan. Spread fruit filling on top. Freeze for one hour, then place the second half on top. (If doing two layers, repeat for the second layer.) Freeze for an additional hour.

Remove from the freezer 20 minutes before serving and take the cake out of the loaf pan, using the overhang of the plastic wrap.

Drizzle with icing, if desired.