Preheat oven to 350°F and grease a 9x13 baking dish.
In a small mixing bowl, place the lukewarm almond milk and dried instant yeast. Combine with a whisk and set aside for 10 minutes to allow the yeast to become activated - the mixture will become frothy.
In a large mixing bowl, whisk together the caster sugar, flour, cinnamon, mixed spice, nutmeg, and salt.
Create a well in the center and pour in the melted butter, vanilla extract, and the yeast mixture.
Mix until a dough begins to form.
Transfer the dough onto a well-floured surface and knead until smooth and soft, about 10 minutes. Alternatively, you could mix and knead in a stand mixer fitted with a dough hook. It will be slightly tacky but not sticky. Knead in more flour if it is too sticky.
Add the orange zest and sultanas, and knead together until well combined.
Place the dough in an oiled bowl and cover with a damp tea towel. Leave in a warm place for an hour, or until dough has doubled in size.
Punch down the risen dough and divide into 12 equal pieces. Roll each piece into a smooth ball.
Place each ball in prepared baking dish.
Cover the baking dish with a damp tea towel and leave in a warm place to rise and double in size, about 45 minutes.
While the buns are rising, make the paste for the crosses by combining the flour and water together in a small bowl.
Transfer to a piping bag or ziploc with the corner cut off.
Once the buns have risen, pipe a cross shape onto each bun.
Bake for 20-25 minutes, or until the buns are golden brown and cooked through.
Make a glaze for the buns by whisking together the apricot jam and maple syrup. Brush on the glaze while the buns are still warm and then serve.