Cake can mean both luxurious and fairly common food. A typical breakfast for the upperclass Georgians, for example, would include pound cake (which I love), rolls (warmed and not), plum cake, hot chocolate, tea and bread. Sugar also goes into bread of course. Lunch tended to be light and often feminine, so after eating all the sweet food for breakfast, a woman would continue that with a small sweet cake or a sweet pastry. Supper would call for a 'tea board' with sweet cakes, biscuits, pastries and rolls, as well as, of course, tea. So the cakes would vary from small cakes similar to rock cakes. More extravagant desserts were now becoming more French and Italian, or was jelly, blancmange or marzipan still. Crystallised flowers were popular too.

Some food, such as Chelsea buns still eaten today, were popular, rich and poor alike: “I soon turned the corner of a street which took me out of sight of the space on which once stood the gay Ranelagh. … Before me appeared the shop so famed for Chelsea buns, which for above thirty years I have never passed without filling my pockets... These buns have afforded a competency, and even wealth, to four generations of the same family; and it is singular that their delicate flavour, lightness, and richness, have never been successfully imitated.” – Sir Richard Phillips, “Morning’s Walk from London to Kew,” 1817.

King George III himself, along with his wife and children, bought buns from there. As well as bun shops, there was also street food, according to Gentleman's Magazine: 'Chelsea Buns formed a frequent cry in the streets of London during the last century, and were as popular as the Bath Buns of the present time. The cry (or rather song) was ” Chelsea Buna, hot Cheheii Buns, rare Chelsea Buns! ” Good Friday was the day in all the year when they were most in request; and the crowds that frequented the Bunhouse on that day, is almost past belief.'

More extravagant cakes were made as well, for example, Twelfth Cake. It would be large and beautiful decorated. 'Take seven pounds of flour, make a cavity in the centre, set a sponge with a gill and a half ofyeast and a little warm milk; then put round it one pound of fresh butter broke into small lumps, one pound and a quarter of sifted sugar, four pounds and a half of currants washed and picked, half an ounce of sifted cinnamon, a quarter of an ounce of pounded cloves, mace, and nutmeg mixed, sliced candied orange or lemon peel and citron. When the sponge is risen, mix all the ingredients together with a little warm milk; let the hoops be well papered and buttered, then fill them with the mixture and bake them, and when nearly cold ice them over with sugar prepared for that purpose as per receipt; or they may be plain.' John Mollard, The Art of Cookery, 1803.

As an idea of how important cakes are, this is a poem by Jane Austen: If the vicar you treat, You must give him to eat, A pudding to hit his affection; And to make his repast, By the canon of taste, Be the present receipt your direction.

First take two pounds of Bread, Be the crumb only weigh’d, For the crust the good house-wife refuses; The proportion you’ll guess, May be made more or less, To the size that each family chuses.

Then its sweetness to make Some currants you take And Sugar of each half a pound Be not butter forgot And the quantity sought Must the same with your currants be found

Cloves & mace you will want, With rose water I grant, And more savory things if well chosen; Then to bind each ingredient, You’ll find it expedient, Of Eggs to put in half a dozen.

Some milk dont refuse it, But boiled ere you use it, A proper hint this for its maker; And the whole when compleat, In a pan clean and neat, With care recommend to the baker.

In praise of this pudding, I vouch it a good one, Or should you suspect a fond word; To every Guest, Perhaps it is best, Two puddings should smoke on the board.

Two puddings! – yet – no, For if one will do, The other comes in out of season; And these lines but obey, Nor can anyone say, That this pudding’s with-out rhyme or reason.

This was for bread and butter pudding. Cakes were common but so were general puddings like this. I would think #2 would be better phrased as desserts in general.

I'll get back with some Georgian recipes if you want.

Sugar in tea was common. There was a LOT of sugar. Looking at an average sugar bowl at the time would make you wonder how anyone had teeth left. Sugar was expensive, originally, although not hideously expensive. So to use a lot of sugar in your tea was a sign of wealth- perfect if guests came around (like the people who rented pineapples, showing wealth was very important). You would get sugar in a kind of cone shaped thing, large and strangely heavy. The servants would cut off bits of the cone so each sugar cube would be a different shape and size when they reached the sugar bowl. So how much sugar they had in their tea, we can't really know- some lumps might have been the size of two mdoern ones!

I can't find an example for tea, but this was a recipe for hot chocolate: 1 quart milk 4 ounces chocolate without sugar 1/8 ounce fine sugar 1/8 ounce flour or starch Salt to taste. (John Nott's Recipe book, 1720s). Chocolate would have been very bitter so they would have used much more sugar in this.

I'm going off the initial question about the use of sugar produced by sugarcane plantations in the New World. I feel like I should add that there is a significant by-product of sugar production - molasses. What is molasses? When you refine sugar, this is a by-product of that process. What are the uses of molasses? One very significant use is rum production. After this distilling of molasses is figured out in the Caribbean in the 17th century, it spreads and eventually New England develops a significant industry in distilling rum.

Anyway, back to what they used sugar for, Europeans used sugar for more than just tea and cake. Overall consumtion of sugar exploded in the later 17th century and during the greater 18th century. There were coffees, cocoas, jams, candies, and other food products using sugar. Common class people could finally get their hands on sugar for use in their food. The subject of sugar is also a popular history subject - a simple amazon book search results in a number of books discussing the history of sugar. In terms of sugar's significance to history, it's high up on the list of significant things. In terms of other materials equal to or more significant than sugar influencing history, you'd have to look to salt and tobacco.

EDIT: Just realized others posted similar answers to mine about 10 minutes ahead of me. Didn't refresh page.