Beat the butter and sugar together
until pale and fluffy. Beat in the vanilla
for a few secs, then use a wooden spoon
to stir in the flour with ¼ tsp salt. Roll
the dough into 36 small balls (the easiest
way to get this right is to divide the
dough into quarters – each quarter
then makes 9 balls).
Heat oven to 180C/160C fan/gas 4.
Line two baking sheets with baking
parchment. Squish 2 balls of dough
together on the paper, keeping the
‘round’ edges of the balls at the top, but
pinching together at the base where they
meet, so they make a rough heart shape.
Flatten with the palm of your hand to a
biscuit, then press in heart-shaped ‘dent’
for the jam – thumbs and fingers are
perfect for this. Repeat with remaining
dough balls leaving a little space between
each finished heart shape for spreading.
Spoon the jam into a food bag (or
disposable piping bag), snip off the end
and pipe roughly 2-3 tsp jam into the
thumb-heart dips you have made in each
biscuit. Bake for 8-12 mins until pale
golden and crisp. Cool on the trays.
Mix the custard powder and icing
sugar, then dribble in enough water
to make a runny icing. Drizzle all over
the cooled biscuits, allow to set for at
least 10 mins, then serve or store in
a biscuit tin.