The cooling sponge means it’s go time for the filling, so whip the
mascarpone, cream and the remaining olive oil together with a hand
whisk until the cream holds form on the whisk. Too billowy and the
roll will slump. Keep chilled until assembly.

When the sponge has JUST cooled, slide the long paper sheet and
sponge onto a clean tea towel (dish towel) to provide traction for the
roll up. Gently peel off the baking paper (that lined the tin), taking
care not to tear the sponge. The crust will peel away too – this is a
good thing; it will expose the crumb to take in curd! Trim the long
edges off with a serrated knife, using a nice and gentle sawing motion
so the sponge sheet doesn’t tear. Trim the short sides with an angled
cut (so it looks like the shape below when looking from the long side).

Make two deep (but not full) incisions 2 cm (¾ in) apart from the
short end closest to you to easily coax the first tight curl up.

The angled cut on the short ends stops the sponge from bunching up at the
start (the centre of the roll) and the end (the seam side).

Smooth 200 g (7 oz) of the curd as a thin layer over the entire sponge
top. Then smooth over just 300 g (10½ oz) of the mascarpone cream.

The extra curd and cream is to serve. Smear a little cream over the
angled cut ends.

Too much curd and cream will make the roll slippery during the roll-up.

To start the roll, have the short end with the two incisions closest to
you and lift and tuck tightly. Really curl the sponge over into the cream.

The sponge may crack to stay in place – that’s okay.

Cracking lessens as the roll girth increases.

After you have a nice tight start, continue rolling the sponge snugly
by holding the baking paper firmly. Use a smooth and slow roll-up
motion by pulling the paper end up and away from you. Roll all the
way until seam side down. Wrap the paper and then the tea towel
(dish towel) snugly around the roll and chill for 30 minutes to set the
shape before the first slice.

continued …