Grease and line an 8½ x 4½-inch loaf pan with parchment paper, leaving a 2-inch overhang on the longer sides for easy unmoulding.
In a small bowl, mix together ¼ cup (36 grams) of the chopped almonds and 1 tablespoon (9 grams) of the sesame seeds. Set aside.
In a medium, heavy-bottomed saucepan, combine the Redpath® Granulated Sugar, the Redpath® Dark Brown Sugar, water, and salt. Place on medium-low heat until the sugar is completely dissolved and mixture has no sandy feel to it. Increase temperature to medium and stir until it just begins to boil. Do not stir at this point. Clip or insert a thermometer into the sugar mixture, making sure that the thermometer does not touch the bottom of the pan for an accurate reading. Cook the sugar mixture until it reaches 250°F (121°C). This is known as the hard ball stage – a spoonful of the sugar mixture dropped into cold water should harden enough to form into a hard ball that gives slightly under pressure.
While the sugar syrup is slowly reaching the hard ball stage, place a medium-size saucepan with about 2 inches of water onto medium-high heat. Bring to a boil. Decrease temperature to low so the water is just barely simmering.
In a large, heatproof bowl, combine the tahini, almond butter, and vanilla extract. Place the bowl over the pot of hot water, ensuring the bottom of the bowl does not touch the surface of the water, and stir until thoroughly combined and warmed through. Stir in the remaining ½ cup (71 grams) of almonds and the remaining sesame seeds. Keep warm, stirring occasionally.
When the sugar syrup is a few degrees below 250°F (121°C), carefully remove the bowl of tahini from the pot, wiping the moisture from the bottom of the bowl. Once the sugar syrup comes to the correct temperature, immediately remove from heat. If you can, gradually stream the sugar syrup into the tahini mixture with one hand while continually stirring with a heatproof spatula with the other. Or, if you have a partner, have one person stream the sugar syrup into the bowl while the other person stirs it in. Stir until mixture just begins to pull away from the bowl (about 30 seconds); do not overmix, or the mixture will become crumbly.
Quickly transfer the mixture into the prepared loaf pan, smoothing out the top, and sprinkling the reserved almond-sesame seed mixture over the surface of the halva, gently pressing to adhere. Allow halva to cool completely at room temperature. Cover the cooled halva well with plastic wrap and place into the fridge to chill and develop; at least 12 hours (preferably 24 hours or more).
Once ready and set, remove halva with the help of the parchment paper overhangs. With a sharp chef’s knife, cut into slices or slice as desired.
Store in an airtight container in a cool, dry place for up to 2 weeks or in the fridge for up to 3 weeks.