Plant-Based Chai Custard Creams

For the Cookie Dough:

1. Add the butter and sugar to a bowl and cream together for 5 minutes until light and fluffy.
2. Add the vanilla bean paste and mix to combine.
3. In a separate bowl, mix together the flour, custard powder and chai spice mix using a balloon whisk.
4. Add the spiced flour to the butter and mix until just combined.
5. Lightly flour your worktop and turn out the dough.
6. Use your hands to work the dough and bring it all together once it is soft and smooth.
7. Roughly mold the dough into a disc and press down gently to flatten before wrapping tightly in plastic wrap.
8. Put it in the fridge to chill for 15 minutes.
9. Remove the chilled dough from the fridge and roll out on a lightly floured silicone mat or sheet of parchment paper to about 1/8 inch (4 millimeters) thick.
10. Using the cutter of your choice, stamp out the cookies, and add to the prepared baking sheets. Any surplus dough can be re-rolled twice, but after this, the dough will begin to toughen, so be savvy with your dough cutting!
11. Place the pans in the freezer to set for 45 minutes.
12. Preheat oven to 365˚F (185˚C).

While you are waiting for the cookies to set, make the custard buttercream:

1. Add all the ingredients, except the soy milk, to a bowl. Use an electric hand mixer or a balloon whisk to combine until smooth.
2. Add the splash of soy milk at the end to loosen the buttercream, then transfer it to a pastry bag.
3. Once the cookies have set, put one pan into the oven and bake for 13 minutes until lightly golden. Repeat with the second pan. Baking them separately just ensures an even bake across both batches.
4. Leave the cookies to set and harden on the pans for 5 minutes before transferring to a cooling rack to cool completely.
5. When they are completely cool, pipe the custard buttercream onto one cookie, leaving a slight border around the sides, before sandwiching with another cookie. Gently press together so the filling comes to the edges. Repeat for all remaining cookies and filling.
6. Note from Ruby: I like these once they have firmed up a little, so I put my finished cookies in the fridge for about 30 minutes before dunking and demolishing.
7. Keep these stored with no lid on, to keep that cookie snap and freshness at its peak.