1) In a large bowl beat the vegan butter and sugar for 2 to 3 minutes until it looks light and fluffy. Beat in the vegan mayonnaise, lemon zest and lemon juice until everything is all mixed up.
2) In another bowl, mix together the spelt flour, poppy seeds and baking powder. Stir this into the first bowl in two additions, and mix everything until the flour is absorbed. Put a tea towel over the bowl, and chill in the fridge for 30 minutes.
3) While the dough is chilling, you can start making the filling! Cream together the vegan cream cheese, vegan butter, sugar, lemon juice, zest and coloring (if you like). This will be going in between 2 cookies, so if it seems too runny add some more icing sugar and corn starch. Cover this and refrigerate until it is more set and solid (not SOLID, but stiff- still spreadable).
4) After 30 minutes, take the dough out of the fridge, roll out the dough to 1/8"-1/4" thick. If the dough is too wet and sticky to roll easily, knead in some more flour. Cut out cookies with a cookie cutter of your choice. I use a set of fondant cookie cutters, which came with the same shape in three sizes, so I cut all the cookies out with the same size, and then to half of them cut a little window in the middle with one of the smaller cutters so when you make a sandwich with two cookies you can see a little peak of icing through the top). Put the cut cookies on a lightly greased baking sheet, and bake at 350 degrees Fahrenheit for 8 minutes.
5) After the cookies have come out of the oven and cooled, spread some icing on the cookies without a hole in the middle, and put a cookie with a hole in the middle on top. Let them sit for awhile so the icing can set and harden up a little and voillllaaaaaaa!
Source of recipe: I modified this recipe from a Canadian Living magazine.