Preheat oven to 170°C/150°C fan-forced. Lightly grease a 3cm-deep, 17.5cm x 27cm (base) slice pan. Line with baking paper, allowing 2cm overhang at long ends.
Combine sunflower seeds, pumpkin seeds, sesame seeds, oats, and dried fruit in a large bowl.
Place nut butter and honey in a saucepan over low heat. Cook, stirring occasionally, for 3 to 4 minutes or until melted. Bring to a simmer. Cook, stirring, for 3 minutes or until slightly thickened.
Add spread mixture and apple and banana to seed mixture. Stir to combine. Spoon into prepared pan. Using the back of a spoon, press mixture evenly into pan. Bake for 25 to 30 minutes or until golden. Cool in pan completely. Refrigerate for 2 hours. Cut into bars. Serve.