Make the mint syrup by mixing the water, sugar, mint leaves and lemon juice in a small saucepan. Heat to boiling, then remove from heat and set aside.
Prepare the gluten free cake with the water, oil and eggs according to the directions on the box.
Make the pudding by whisking the two cups of milk into the pudding mix. Refrigerate to set.
Once the cake is baked, let it cool down to room temperature. Then, cut the cake into 2-inch squares.
Prepare the trifle by making a layer of gluten free chocolate cake squares along the bottom of a trifle dish, or a large, preferably see-through dish. Use a spoon to drizzle about 1 tablespoon of cooled mint syrup over the cake. Next, spread a layer of the pudding/whipped cream mixture over the cake. Then, layer about 1 ½ cup of fresh strawberries over the pudding.
Repeat the layers, ending with the whipped cream topping. Garnish the gluten free strawberry mint chocolate trifle with fresh strawberries, whole mint leaves, and minced mint leaves, if desired.
Refrigerate at least 2 hours, and up to 24 hours, before serving.
If you really like pudding, you may want to make two boxes of vanilla pudding, and double the amount of whipped cream called for in the recipe. Then, use two big layers of the pudding/cream mixture when making the trifle. Also, I made the fruit layer rustic, but you can certainly line the sliced strawberries along the side of the bowl to make a more dramatic serving presentation, if desired.