01 -
Set oven to 150°C and line a 9-inch fluted tart pan with a removable base.
02 -
Combine flour, icing sugar, salt, grapefruit zest, and thyme in a food processor. Pulse briefly to blend.
03 -
With processor running, add cold cubed vegan butter gradually until the dough forms a rough ball.
04 -
Press dough evenly into the tart pan, ensuring an even layer throughout.
05 -
Transfer pan to oven and bake for 35–40 minutes, until firm and lightly golden at the edges.
06 -
Remove baked shortbread and, while warm, use a sharp knife to cut into 16 equal wedges. Cool completely in the pan before lifting out.
07 -
Gradually whisk grapefruit juice into sifted icing sugar, adjusting juice for desired consistency. Add gel coloring if using.
08 -
Once cookies are cool, dip tops into icing for a smooth layer. Place on wire rack and repeat for a second coat on all wedges.
09 -
Decorate with fresh thyme or pearl sugar and let sit until icing is set and dry before serving.