Coconut sugar gives this cake its dark caramel colour but it has a lemon zing from my homemade sugar-free lemon curd. Recipe is here.

2 3/4 c flour (I used a mix of white and wholemeal spelt. You can use gluten-free flour)
2 tsp baking powder
1/4 tsp baking soda
1/4 tsp salt
1 1/2 c granulated sugar (I used ground coconut sugar)
85 g butter or non-dairy spread
1/3 c neutral oil (I used rice bran)
2 large eggs
1/2 tsp vanilla extract
1 generous cup lemon curd
1 tbsp lemon zest
1 cup milk of choice or buttermilk (I used yoghurt and rice milk mix)

Icing:
2 c icing sugar
lemon juice
lemon zest if desired

Preheat oven to 180C. Grease a 10-12 cup bundt pan.
In a bowl sift the flour, baking powder, baking soda and salt. In another bowl cream the sugar and butter in a stand mixer, hand mixer or by hand, until light and fluffy. Beat in oil, then eggs, then vanilla. Add about 1/4 c lemon curd and zest and mix to combine. Fold in half the flour mixture until just combined. Pour in milk and rest of flour and fold gently until combined.
Pour half the batter into your bundt, spoon in rest of lemon curd evenly on top, then cover with rest of batter. Tap the pan a few times to get rid of any air pockets within the batter. Bake for 40-45 min until just cooked through. Cover with foil halfway through if the top is browning too much and forming a thick crust. The top of the cake should spring back when lightly pressed.
Remove from oven and let cool in the pan for about 15 minutes before turning out onto a wire rack to cool completely.
Mix the icing sugar with enough lemon juice to achieve a thick but pourable icing. Drizzle over cake and sprinkle with more lemon zest if desired.