Virtual Furnace

VirtualFurnaces allow you to create fully functioning portable furnaces... as items.
Let's go over some of the main elements of this system.

Fuels

Creating items

Now that we have our virtual furnaces set up, let's create an item.
This is a bit more complicated so let's break it down.
Syntax:

[a] [(glowing)] virtual furnace item as %itemtype% with (inventory|gui) name %string% [[and ]with cook speed multiplier %number%] [[and ]with fuel speed multiplier %number%]

Glowing = If the item will glow like an enchanted item.
item as ItemType = This will determine the item we use as our virtual furnace item. This accepts any item type Skript allows, including items with names, lore, etc.
gui Name = This will be the name that appears in the GUI when the player opens their virtual furnace.
Cook speed multiplier = This optional value will determine the cook speed multiplier for this virtual furnace. Default value = 1.0, meaning it will cook based on your recipes. IF you use a value such as 2.0, the item will cook twice as fast as determined by your recipe.
Fuel speed multiplier = This optional value will determine the fuel speed multiplier for this virtual furnace. Default value = 1.0, meaning the fuel will burn as fast as determined by your registered fuel. IF you use a value such as 2.0, the fuel will burn twice as fast.
Example:

set {_a} to a diamond named "MyPortableFurnace" with lore "Right-Click to access your personal furnace"
set {_b} to a glowing virtual furnace item as {_a} with gui name "Portable Furnace"
set {_c} to a glowing virtual furnace item as {_a} with gui name "Portable Furnace (x2)" with cook speed multiplier 2.0
give player {_b}
give player {_c}