In a large bowl or food processor whisk together the flour, sugar, baking powder, zest, salt. Add the butter, milk, egg, vanilla and lemon juice, pulse or mix by hand or flat beater until almost formed into a dough. If the dough is too wet add a bit more flour if too dry a bit more milk.
Move the dough to a lightly floured flat surface and gently knead to form a compact not sticky soft dough. Wrap in plastic wrap and chill for one hour.
Form the dough into golf ball size balls (or a bit bigger if you prefer), place on 1-2 parchment paper lined baking sheets 1-1½ inches apart. Chill while the oven is pre-heating, approximately 15-20 minutes.
Pre-heat oven to 350F/180C.
Bake for approximately 15 minutes or lightly golden. Let cool 10 minutes on the pan then move to a wire rack to cool completely. Lightly dust with powdered/icing sugar before serving. Enjoy!
Notes
How to store the cookies?
Store the cookies in an airtight container at room temperature for up to 3 days. They can also be frozen for up to 2 months; thaw at room temperature before serving.If the dough feels sticky, it may need a bit more chilling time. You can also lightly flour your hands or add a small amount of flour, just until the dough is easy to handle. Alternatively, if the dough is too dry, add a bit more milk.