In the bowl of a stand mixer fitted with the paddle attachment, beat the Becel and sugar on high until light and fluffy, about two minutes.

Using a rubber spatula, scrape down the sides of the bowl. With the mixer on low speed, add the eggs and the vanilla extract, mixing until combined.

With the mixer on low speed, add the flour until a dough forms; do not overmix.

Turn the dough onto a large piece of plastic wrap; form into a flat disc, then refrigerate for 2 hours or overnight.

Remove the dough from the fridge. On a flour-dusted work surface, roll the dough out to 1/2 inch thickness. Punch out mushroom shapes using a large mushroom cutter, or use large and small mushroom cutters for cute variance!

Carefully lift the cut shapes and place on a parchment paper lined baking sheet. Chill in freezer for 15 minutes.

In the meantime, preheat the oven to 350 degrees °F.

Bake the cookies for 9-11 minutes, turning pans halfway to ensure even baking, until cookies are lightly browned. Let cool completely on wire racks before frosting!

In the bowl of a stand mixer fitted with a paddle attachment, beat the Becel, icing sugar and pure vanilla extract on high speed until light and fluffy and doubled in volume, about two minutes.

Divide buttercream evenly into two medium bowls. Tint one bowl with the red gel food colouring, mixing until combined.

Set the completely cooled sugar cookies on a clean work surface.

Fill a piping bag fitted with a multi-opening grass tip with the red buttercream.

Fill a piping bag fitted with a small open-star tip with the white buttercream.

Pipe the top of the cookie mushroom cap with the red buttercream in short spurts.

Pipe the bottom stem of the cookie mushroom with white buttercream drop stars.

On the piped mushroom cap, carefully add the white candy pearls in an even and eye-pleasing pattern.

To decorate a cake with these cookies, press the cookie gently into a buttercream-topped cake, anchoring each cookie using a hidden wooden BBQ skewer cut to size to help hold up the cookie.