Milk chocolate (reverse) ganache
Flip the classic hot cream ganache rule on its butt! By melting
your chocolate and adding cool cream, you are at peak gloss
and spreadability without a tedious wait for it to thicken.

You can also apply this technique for mid cocoa-level dark
chocolate or white. Same ratios of chocolate to sour cream,
same  deliciousness and same instant success!

Big baking love to Rose Levy Beranbaum for this technique –

my baking hero and author of The Cake Bible and other

must‑own-and-make-every-recipe bakebooks.

Temperatures are paramount to avoid the chocolate cooling and forming
lumps in the ganache. Aim for milk chocolate at 50–60°C (120–140°F) and
sour cream at 20°C (70°F). On cold days, take the sour cream out of the
fridge an hour before starting.

Weigh the sour cream into a small bowl and leave at room temperature.

Bring a small saucepan of water to a bare simmer. Weigh the milk
chocolate into a bowl that nestles on top without touching the water.

Push the chocolate around the bowl until it has melted – don’t agitate
it too much.

When the chocolate has melted, do a temperature check. If the sour
cream is still cold, hold the bowl over the double boiler for a minute,
stirring slowly and constantly only to take the refrigerator chill out of it.

Scrape the sour cream into the chocolate and mix to form a smooth,
glossy and firm–gloopy mix. If you need it a bit thicker, leave it to cool
for 10 minutes, but don’t chill it without keeping a close eye to ensure
it doesn’t over-chill and become unspreadably hard.*

* If you did chill it and it hardened, put the bowl over the still-warm double boiler
and gently soften. The ganache may look less smooth after a reheat, but it’s
still  usable.

Makes 300 g (10½ oz). Takes 20 minutes. Keeps Up to 2 weeks chilled.

150 g (5½ oz) full-fat
(35% milkfat) sour cream
(not crème fraîche – it’s too
high in fat)
150 g (5½ oz) good milk
chocolate (30%-plus cocoa),
roughly chopped
Adaptrix
Dark chocolate
Use the same process, but I like
to keep my dark chocolate around
55–60% cocoa. If you use a 70%
cocoa, increase the sour cream by
50 g (1¾ oz) so it’s still luscious.

White chocolate
This reverse ganache Adaptrix will
be softer because it’s only cocoa
butter (not solids). It will firm enough
to use for a cake coat, but isn’t up to
long-term structural layering duties.

Regular cream ganache
Sub in a regular 35% milkfat cream
for the sour cream. If your cream is
runny, the ganache will take extra
time to reach spreadability. It’s still
hands-down faster than the hot
cream on chocolate method, though.

Shine shine shine
If your ganached cake dulls in cold
weather, sweep a brûlée torch
over the surface to rekindle the
cocoa  lustre.