Preheat the oven to 170°C (150°C Fan Oven, Gas Mark 3). Arrange 6 x 10cm diameter mini non-stick bundt tins, ungreased, on a large baking tray. Mix the milk and lemon juice together and set aside.
Sift the flour and Bicarbonate of Soda into a bowl. Stir in the sugar and make a well in the centre. Mix the eggs, melted butter and Vanilla Extract together and pour into the well. Add the milk and stir until well blended and batter-like.
Divide the batter between the tins to half fill them and bake for about 15 minutes, until risen and golden. Stand for 5 minutes to firm up then turn on to a wire rack to cool.
To decorate, sift the icing sugar into a bowl. Add the Vanilla Extract and approx. 15ml (1 tbsp) warm water to form a thick, drizzling icing. Spoon the icing over the bundt cakes allowing the icing to drizzle down the sides. Leave for a few minutes to firm up the icing before serving.