Set the oven to 170 C. Line an 8in/ 20 cm tin with parchment paper
Mix the flour, baking soda, poppyseeds, salt together until combined (by stiring or by whisk)
Mix the milk, oil, vanilla, sugar, zest and orange juice together. Whisk to combine. Add the vinegar to the liquids and whisk or stir together just before combining with the dry ingredients. The vinegar will react with the other ingredients to facilitate a rise in the cake.
Stir the cake until only just combined ( it can become tough)
Pour into the prepared tin and bake straight away. Bake for approxximately 25 minutes or until a skewer inserted into the cake comes out clean.
Cool until the cake tin is cool enough to be touched. Run a knife around the edges of the cake and turn out. Cool completely