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Crunchy yet tender, sweet and high in calories, there’s a peculiar Italian snack which is sandwiched between two pieces of Christian communion wafers.

The ostie piene, or “filled hosts” – a mouthwatering mix of almonds and honey stuffed between two wafers – are one of Italy’s most delicious cookies.

And they could also be one of its most sacrilegious if not for the fact that the two translucently thin wafers intended to tantalize tastebuds with their sublime filling have not, of course, been consecrated by a priest.

Called ostie ckiene in local dialect, they’re the traditional sugary treat of Monte Sant’Angelo, a village in Puglia’s pristine Gargano National Park.

Monte Sant’Angelo has layers of dazzling white houses and a cave-church believed to have been consecrated by the Archangel Michael, which has been a major pilgrimage site since the Middle Ages.

The locals are extremely religious but also sweet-toothed, and don’t see anything sacrilegious in the ostie piene, which were said to have originated inside the village convent of Santissima Trinità at least 500 years ago.

A spiritual calling card

Monte Sant'Angelo is an important pilgrimage spot for the Catholic faith.

Spirituality and cakes here are deeply intertwined.

“I have been making ostie piene for 40 years, they’re part of our tradition, our business card: wherever we go, we bring them as gifts and we eat them year-round, at any time of the day and week. They’re not just for special occasions,” local pastry maker Gino Bernabotto tells CNN.

He says they’re easy to prepare, with a few basic ingredients: flour, water and extra virgin olive oil for the wafer, which is molded inside a heated metal press called ferrate, plus local wildflower or acacia honey and premium toasted almonds from Puglia’s countryside for the filling. Sugar and cinnamon add to the flavor.

“It’s a healthy snack without any added preservatives. The secret lies in the selection of the almonds which must be all of the same size, rather big, flat, with an even surface and oval to stick well to the honey and hold together the two hosts,” says Bernabotto.

The almonds are used whole, and the delicate taste of the tender ivory-colored wafers contrasts with the strong-flavored golden filling.

Innocent mistake or edgy recipe?

Locals think they could have been a delicious mistake by nuns.

Legend goes the ostie piene were the result of a culinary mistake made by the convent’s Poor Clare sisters in the 17th century while they were preparing a cake with a honey-almond mix and inadvertently dropped a scorching spoonful of it on the floor or kitchen counter.

To scoop it up and avoid being burnt, instead of a spoon the pious sister used a communion wafer which they were also preparing for the upcoming Sunday mass. The honey stuck to the wafer in such a perfect way that the blunder turned into a deliciously sinful treat.

Another version of the tale goes that the nuns used two wafers to pick up a few almonds that had dropped by mistake into a pot of honey, and then glued them together, sandwich-style.

However, other locals believe it was actually an intentional creation and that ostie piene are a real recipe invented by the nuns as sugary treats, likely with leftover or flawed wafers. In the past convents were places where both food and wafers were prepared, alongside honey, and some of Italy’s best loved desserts were first made by nuns.

According to local historian and author Alberto Cavallini, the nuns used what was always available inside their kitchen: round communion wafers, almonds picked from the convent’s groves, and honey from the convent’s beehives.

“The nuns regularly made the communion wafers by cooking them on iron plates and then cutting off the edges to give a round shape – this recurring preparation probably inspired them to create also a cookie made in the same way,” says Cavallini.

Whether it was a kitchen slip or not, historical records verify the origins.

In 2015, documents found by Cavallini confirmed ostie piene were traditional cookies prepared within the cloister walls and gifted to guests and pilgrims.

“There’s a 17th-century abbot from Naples, called Giovan Battista Pacichelli, who visits the village and writes in his travel memoirs that the nuns from Monte Sant’Angelo made exquisite wafers stuffed with almonds and honey for the feast of St. Michael,” says Cavallini.

In one of his books Cavallini also mentions the diary of a 17th-century nun called Donna Constantia Jordana who writes that her abbess would welcome priests and travelers visiting the village during religious celebrations with the ostie piene “prepared by us sisters.”

Shipped across the kingdom

The cookies have a centuries-long history.

Two hundred years later, according to another source unearthed by Monte Sant’Angelo’s authorities, Neapolitan cook Vincenzo Corrado who worked in aristocratic households writes about the success of ostie piene.

In one of his gastronomy essays Corrado reports that by the 19th century the convent cookies had become so trendy they were sold and shipped across the entire southern Kingdom of Naples.

Their popularity was largely due to the delicious local nuts. Ancient almond groves that dot the Gargano hills with blooming white flowers in springtime and spontaneously grow on abandoned land are believed by locals to be a symbol of prosperity and wellbeing.

Musician Peppe Totaro, who hails from a family of pastry chefs and each year organizes Monte Sant’Angelo’s tarantella popular music festival, complete with stands of typical foods and heaps of cookies, still recalls when as a 10-year-old kid he’d help his father prepare the ostie.

“We had to weigh and measure each single almond to make sure they were all similar and regular in size. Farmers would come with their carts full and we’d sit there for hours, analyzing them all.”

During the Roman Catholic Church’s “great jubilee” year of 2000, visitors who flocked to Monte Sant’Angelo were amazed to see such weirdly shaped cookies, says Totaro, which they thought were real, gourmet sacramental wafers.

Totaro is keen to stress a key distinction: “The ostie piene dough is made in the same way as the wafers, but the wafers become sacramental only during the holy communion. These are just cookies.”

Served with a boozy side

The almonds must be selected to be the same size and shape.

Ostie piene come in all sizes, and are more oval rather than round. Even though every village pastry shop and household make their own variants the traditional ones are huge as a hand – exactly the same size as the main holy wafer held by the priest at the altar.

There are also smaller ostie, less popular, around the same size as a medal, which are cut out from the larger wafer with a stamp.

Prices are reasonable: Bernabotto sells a box of 20 small cookies for €5 (about $5) while four large wafers cost €4.

“They’re very nutritious, the almonds and honey are energy boosters and their benefits have been re-evaluated by nutritionists. It’s a simple, minimalist cookie but with rich ingredients”, he says.

Totaro warns not to add too much sugar or the ostie will be too sweet and hard to bite, and suggests that just a drop of lemon will make them even more soft.

The best way to savor ostie piene is with an after-meal homemade laurel liqueur or with Monte Sant’Angelo’s famous alcoholic drink Limolivo, made with olive oil leaves.

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