Step 1Lightly spray a 21cm x 11cm loaf tin with oil and line with cling wrap, allowing wrap to overhang on the long sides of the tin.
Step 2Lightly score the base of each peach with a cross. Bring a large saucepan of water to the boil. Add peaches; simmer gently for 2 minutes. Remove peaches with a slotted spoon and transfer to a large bowl of iced water to cool. Once cool, carefully remove the peach skin with a small sharp knife and discard. Cut peaches into chunks and discard stone.
Step 3Blend or process peach chunks into a smooth puree. Place half of the ice cream into a bowl and set aside to soften slightly. Add the peach purée and almonds; stir until well combined and smooth.
Step 4Spoon the peach ice-cream mixture into prepared tin and smooth surface. Cover tin with overhanging wrap and place in freezer until firm.
Step 5Once peach layer is firm, place raspberries in a large bowl, and crush with a fork. Add remaining ice cream to bowl, and set aside to soften slightly. Stir raspberry ice-cream mixture until smooth and well combined. Spoon the raspberry mixture evenly over the layer of peach ice cream; cover and return to freezer until firm.
Step 6To serve, remove terrine from tin using cling wrap as handles and invert onto a serving platter with the peach layer on top. Top with extra raspberries and slice evenly to serve.