Place apples, pears and cinnamon in a deep pan with half a cup of water.Bring to a boil and simmer on low heat till apples and pears are softened.
Remove from heat, discard cinnamon and let cool completely. Place fruits and yogurt in a blender and churn till smooth.
Add sugar substitute to taste. Spoon into four individual tall glasses and keep in the refrigerator to chill.
Spread out the porridge oats and almonds in a baking tray and place under hot grill until lightly toasted.
Shake the pan frequently. Let cool completely.
Sprinkle oats-almond mixture on chilled fruit yogurt fools just before serving.