There seems to be at least three different versions of Praline around at the moment here is my attempt at to explain some of the differences and history.
European nut pralines
We think that the princely Praline may have originally been discovered in France and an accident/the work of chef Clement Lassagne, chef who worked for Marshal du Plessis-Praslin (1598–1675), and named in his honour
The first pralines would have most likely been whole almonds that had been caramelised sugar, as opposed to a dark toffee like sheet of caramelised sugar covering roasted nuts like almonds or hazelnuts.
The powder made by grinding up these caramel-coated nuts is then called praline, today it is used as an ingredient in cakes, pastries, and ice creams. When the powder is mixed with chocolate, it becomes praliné in French, which in turn gave birth to what is now known in French as chocolat praliné.
Belgian soft-centre pralines
Pralines from Belgium are also known as " Belgian chocolates", "Belgian chocolate fondants" and "chocolate bonbons" in English-speaking countries — cases of chocolate (if from Belgium usually a quality, branded lower-melting point Belgian chocolate) filled with a soft centre.
Jean Neuhaus was a Swiss with Italian roots. When he arrived in Switzerland, Jean's family changed its name from "Casanova" to "Neuhaus". He wanted to become a doctor to help people and so he went to study medicine in Grenoble. He failed mainly because the sight of blood made him feel ill. He then moved to Brussels in 1857. he opened a pharmacy in the Queen's Gallery. To tempt his customers, Neuhaus covered his medicines with a fine layer of chocolate. (a spoonful of sugar) His grandson Jean Neuhaus II, introduced chocolate pralines as a chocolatier, in 1912 and the rest is history as they say.
Today there are lots of different types and shapes: mostly consisting of a chocolate shell with a softer filling sometimes layered. Confusion arises over the use of the word praline in Belgium it can refer to a traditional praline filling common acrosss Europe caramelised hazelnuts or almonds ground into a paste, sometimes with condensed milk or cream described as praliné. Both are amazing.
In 1915, Louise Agostini, Jean Neuhaus Jr.'s wife, invented an elegant gift box to protect and present the chocolates. The ballotin has gone on to be a standard in chocolate packaging.
American cream-based pralines (pecan candy)
In the 19th century French settlers brought a recipe to Louisiana, where both sugar cane and pecan trees were plentiful. New Orleans, emancipated black women substituted pecans for almonds, added cream to thicken the confection, and thus created what became known throughout the American South as the praline.
Pralines have a creamy consistency, similar to fudge. They are usually made by combining sugar, butter, cream or buttermilk, and pecans in a pot over medium-high heat, and stirring constantly until most of the water has evaporated and it has reached a thick texture with a brown colour. This is then usually dropped by spoon onto wax paper or aluminium foil greased with butter, and cooled.