Ginger, pear and pistachio crumbles

Ingredients

• 6 medium firm pears, peeled, chopped coarsely
• 125 g fresh or frozen raspberries
• 2 tbsp cornflour or arrowroot
• 1 tbsp finely grated fresh ginger
• 1/4 cup pure maple syrup, plus 1/4 cup extra
• 1 tbsp lemon juice
• 1 tsp vanilla extract, plus 1 tsp extra
• 1 cup pistachios
• 1 cup pecans
• 1 cup rolled oats
• 1/4 cup olive oil
• 2 tbsp freeze-dried raspberries
• 2 cups thick no-sugar-added vanilla yoghurt (see notes)