Line a 20-cm (8-inch) square pan with plastic wrap and lightly oil.
In a saucepan, combine all the ingredients except for the maple extract and bring to a boil, stirring with a wooden spoon to dissolve the sugar. Attach a candy thermometer in the centre of the pan and simmer over medium heat without stirring until the thermometer reads 116 °C (240 °F). Add the extract without stirring.
Place the pan in a cold water bath. Cool, without stirring, until the thermometer (always at the centre of the pan) reads 55 °C (130 °F), about 20 minutes. (If you put the thermometer on the rim of the pan, the cooling temperature should be between 43 and 50 ° C (110 °F and 122 °F).
Remove the pan from water. Using an electric mixer with a single beater or a wooden spoon, stir vigorously until the mixture begins to lighten in color and become creamy, about 2 to 3 minutes. Please note that if you whip too much, the sugar and cream mixture will harden before you have time to pour it into the pan.
Pour immediately into the pan and smooth with a spatula. Cover with plastic wrap and press to smooth the surface. Let cool for about 1 hour at room temperature or 30 minutes in the refrigerator.
Remove from the pan and remove from the plastic wrap. Cut into squares. Store in an airtight container.