Place a large, ungreased cookie sheet or sheet pan near your stove to be ready when the toffee is finished cooking.

In a medium-sized saucepan or deep skillet, add the sugar to the center of the pan. Slowly pour the water directly over the sugar, then add the corn syrup and butter. This layering method helps prevent the candy from becoming grainy.

Set the pan over medium-high heat and bring to a simmer without stirring. Once the butter melts, add the almonds and begin stirring continuously with a wooden spoon to ensure even cooking. If using a candy thermometer, attach it at this stage.

Continue stirring constantly until the mixture thickens and develops a warm amber hue, similar to peanut butter. This typically takes 10 to 15 minutes and should register between 295°F and 300°F on a candy thermometer. Lower the heat slightly as needed to avoid burning.

When the almonds are light brown and the candy mixture reaches the correct temperature, carefully pour it onto the prepared cookie sheet. Use a fork or spatula to spread the mixture as thinly as possible before it begins to harden.

While the almond toffee is still hot, distribute the chocolate pieces evenly over the surface. Allow the chocolate to soften for 2–3 minutes, then spread it gently into a smooth layer using an offset spatula.

Let the Almond Roca cool completely at room temperature until firm. Once cooled, lift the toffee from the sheet and break it into small pieces. Store in an airtight container at room temperature for up to two weeks.