Cut bananas into three pieces and insert a popsicle stick into each piece, being careful not to push all the way through.
Pour melted peanut butter into a tall glass. Dip each banana piece into the peanut butter, allowing excess to drip off. Place onto a parchment or silicone-lined baking sheet.
Freeze for at least 4 hours, or until fully firm.
Melt the dark chocolate and stir in coconut oil (if using) until smooth. Transfer to a tall glass.
Dip each frozen banana into the chocolate, gently shaking off excess.
Place back onto the baking sheet and freeze again until set.
Store in the freezer and enjoy straight from frozen!