Raspberry coulis is an easy way to pretty up freshly baked molten lava cakes for company. Don't drain the raspberries- you want all that raspberry juice in the sauce. You can use frozen strawberries if you prefer strawberry coulis.
In blender, purée raspberries and their juices, sugar and lemon juice until smooth. Pour through a fine-mesh sieve set over a bowl. Using rubber spatula, press purée through sieve. Discard solids. Refrigerate coulis.
Preheat oven to 425°F (220°C). Generously butter six ¾-cup (175 mL) ramekins.
In bowl, combine cake mix, eggs and melted butter. Using wooden spoon, stir for 30 seconds to moisten. Scrape side of bowl. Stir for 1 minute. Batter will be very thick. Spoon evenly into prepared ramekins. Place ramekins on baking sheet. Bake in centre of oven for 8 to 9 minutes or until edges are set but centre is still soft. Remove from oven and let stand for 5 minutes.
Spoon 2 tbsp (25 mL) coulis onto each of six dessert plates. Carefully invert one cake onto each of the plates. Dust with icing sugar and garnish with a mint sprig, if desired. Save remaining coulis to drizzle over ice cream or yogurt.