In a small skillet over medium heat, prepare the almond crunch layer by combining the chopped almonds, brown sugar, water, and salt.

Cook, stirring continuously, until the brown sugar is dissolved and the almonds are well coated, about 2 minutes.

Scrape the almond mixture out onto a piece of parchment paper and spread it into a single layer.

Let it cool completely, then break up any larger chunks into smaller pieces.

Meanwhile, combine the chopped nectarines, brown sugar, water, and almond extract in a medium saucepan over medium-high heat.

Bring the mixture to a simmer and cook, stirring occasionally, until the nectarines are soft and almost broken down, about 10-12 minutes.

Remove the saucepan from the heat and set it aside to cool.

Once the nectarine mixture has cooled, transfer it along with any accumulated cooking liquid to your blender.

Add the Greek yogurt and pulse everything together 4-5 minutes, stopping to scrape down the sides of your blender as necessary. You want the mixture to be mostly smooth, but still have some "flecks" of nectarine remaining.

Divide the nectarine-yogurt mixture between your popsicle molds, filling each mold about 2/3 the way full.

Add some of the almond mixture into the top of each mold, pushing it down slightly.

Insert your popsicle sticks and place your popsicle molds in the freezer.

Freeze until the popsicles are completely firm, about 6-8 hours.

Once completely frozen, the popsicles can be removed from their molds and enjoyed.