1.Make cinnamon custard. Blend custard powder, cinnamon and sugar with milk in a small saucepan; stir over medium heat until mixture boils and thickens. Cook, stirring, a further minute. Remove from heat; stir in butter and extract. Transfer to a small bowl; cover surface with plastic wrap. Cool.
2.Peel pear; core and thinly slice. Cut rhubarb lengthways into 1cm (½ -inch) wide long strips; cut strips into 7cm (2¾ -inch) lengths. Cut pomegranate in half crossways; hold one half over a bowl, tap the back with a wooden spoon to release seeds and juice. Strain seeds over a small jug; reserve seeds and juice separately. You need ¼ cup (60ml) juice; make up any difference with water.
3.Preheat oven to 180°C/350°F. Grease an 8-hole (¾-cup/180ml) mini loaf pan; line base and long sides of each pan hole with a strip of baking paper.
4.Beat butter and sugar in a small bowl with an electric mixer until pale and fluffy. Beat in egg. Stir in sifted flour and custard powder. Spoon mixture into pan holes, spreading to cover the base; there will only be a small amount of mixture. Top with cinnamon custard (about 3 teaspoons per hole), spreading carefully over cake mixture. Alternate pear and rhubarb slices upright on top of custard; sprinkle with pomegranate seeds.
5.Bake cakes for 25 minutes or until a cake springs back when pressed lightly with finger.
6.Meanwhile, stir reserved pomegranate juice and extra sugar in a small saucepan over low heat until sugar dissolves. Bring to the boil; boil for 5 minutes or until thick and syrupy.
7.Stand cakes in pan for 5 minutes before lifting out onto plates. Brush top of warm cakes with warm syrup; serve cakes warm.