The reaction of Maillard is a reaction between a sugar and a protein. The sugar should be a reducing sugar, meaning that the sugar has to have the possibility to react with an amino acid (protein). Examples of reducing sugars are fructose and glucose. Saccharose or sucrose is not a reducing sugar. How comes?
As you see in the picture, glucose and fructose can react with a protein while sucrose should split first in glucose and fructose by heat or acid, which takes more time.
So, in the kitchen we can influence the color of a cookie by using a more reducing sugar or a less reducing sugar. The darker you want the cookie to be, the more reducing the sugar has to be.
Fructose is more reducing than glucose followed by maltose, lactose and sucrose.
As you can see in the picture below, honey (contains fructose) and fructose itself provides a more darker cookie although it is based on the same recipe and baking time.