Candied sweet potatoes – cubes of sweet potato deep fried till crispy, glazed in a sweet sugary syrup and finished with a sprinkle of black sesame seeds – are a delicious and tasty snack. Whereas grilled sweet potato (yaki-imo) is a common sight around Japan in autumn, these candied sweet potatoes (daigaku-imo, literally ‘university potato’) are popular snack often served at university festivals.

So here, we have Nestlé KitKat Yaite Oishii Sweet Potato, a bakeable type of KitKat.

The back of the pack explains how to prepare these bakeable KitKats. When heated in a toaster, the sugar in the chocolate solidifies faster than the cocoa melts, resulting in a KitKat with a different texture.

The construction of the KitKat is standard with two wafers sandwiching a sweet potato cream and enrobed in a sweet potato infused white chocolate.

Without baking – as these can be eaten without a trip to a toaster – these KitKats have the strong smell of sweet potato and taste immensely sweet with pleasant floral notes or sweet potato.

To prepare these KitKat, place them in the refrigerator until cool, then unwrap and place on a baking tray lined with aluminium foil. You’ll want to do more than one because they’re tasty and it’s less effort than turning the oven on every time.

The instructions suggest placing 3-4 minibars into a 1000W oven toaster for 2-2.5 minutes. Oven toasters are common in Asia, likely due to space restrictions. As I don’t have one of them, I placed mine into a fan-forced electric oven preheated to 180°C.

About thirty seconds into the oven, the white chocolate on the KitKats will melt into a puddle. This is normal as is the delicious smell of caramelising sugar.

Give it another minute or so and the chocolate will bubble slightly before starting to crisp up around the edges of the puddle. Wait another minute for the KitKat to turn a golden brown before removing from the oven.

The top did not brown any further after crisping at 4 minutes.

The bottom, however, became a beautiful golden brown.

The resulting KitKat looks more like a cookie than a chocolate bar.

The KitKat smell of freshly baked cookie with a caramelised sugar crust. Upon tasting, it’s deliciously crispy – more so than an ordinary KitKat straight from the fridge – with the sweet floral and earthy flavour of sweet potato developing in the body, with a lingering caramel aftertaste. The hardened enrobing chocolate does not melt in your mouth as in a normal KitKat, while the sandwiching cream takes on a gritty texture not present before baking, thus allowing the KitKat to retain its crumbly cookie texture throughout. The overall flavour recalled the deliciously sticky yet crunchy crust of a daigaku-imo.

These KitKat can also be baked ahead of time, as they retain their tasty crispiness the next day if stored in an air-tight container after allowing to cool.

This pack of Nestlé KitKat Yaite Oishii Sweet Potato contained 13 minibars. It was produced in Japan and purchased in Ōsaka, Japan in 2015.