Grease the savarin molds or muffin tin holes with oil.

Combine milk and butter in a saucepan.

Heat over low heat until butter melts.

Remove from heat and cool to room temperature.

In a large bowl, combine flour, sugar, and yeast on one side, and salt on the other.

Make a well in the center and add lukewarm milk and butter mixture and beaten eggs.

Stir until a soft, sticky dough forms.

Beat in orange and lime zest.

Knead the dough in the bowl for 10 minutes until smooth and elastic, or use a stand mixer with a dough hook for 5 minutes.

Cover the bowl and let the dough rise at room temperature for 1-3 hours until doubled in size.

Knock back the dough and divide it into equal portions depending on the tins you are using.

Place the dough in the tins and cover with oiled plastic wrap.

Let rise for 1 hour until the dough rises above the top of the tins.

Preheat the oven to 400°F/200°C/180°C fan/gas 6.

Bake the babas for 20 minutes if using savarin molds, or 15 minutes if using a muffin tin, until golden brown.

While the babas are cooking, make the soaking syrup.

Place the caster sugar in a saucepan and pour in the orange and lime juices.

Heat over low heat, stirring until the sugar has dissolved.

Turn up the heat and simmer for 2 minutes until the mixture has thickened slightly.

Remove from the heat and stir in the rum.

When the babas are cooked, remove them from the oven and cool for 10 minutes.

Remove the babas from the tins.

Pour a small amount of syrup into the bottom of the empty tins, then return the babas to the tins to soak up the syrup.

Spoon some of the remaining syrup over the babas and leave to cool.

Turn the babas out on to plates and drizzle over the remaining syrup.

Whip the cream into soft peaks.

Pipe it on to the top of the babas and sprinkle with lime zest.