In a small saucepan, caramelize sugar over medium heat until it turns into a dark amber color. Swirl pan as the sugar cooks. Try to avoid stirring the sugar to prevent crystallization. Keep an eye on it as it burns very easily.
Turn off heat, slowly pour in whipping cream. It might splash, be careful. Turn heat on low, cook caramel until it boils, add salt. Take off heat, cool until it is lukewarm, stir in butter and sesame paste. Cool until ready to use. This recipe will yield more than enough for the butterscotch squares, but it makes a great sandwich cookie filling or spread.
Kinako Butterscotch Square Batter
Preheat oven to 350 F / 180 C.
Butter and line an 8 inch square cake pan with parchment.
In a medium bowl, whisk together flour, salt, baking powder, and kinako.
In a medium saucepan over low heat, melt butter, stir in brown sugar to break up any chunks. Take off heat, whisk in eggs and vanilla extract.
Fold the butter mixture in to the dry ingredients with a silicone spatula until there's no more traces of flour. Pour into prepared pan. Heat up the caramel in the microwave oven for about 30 seconds and drizzle it on top of the batter. Sprinkle with crushed walnuts.
Bake in preheated oven for 25 - 30 minutes, until the center is still slightly soft. Cool before serving. To serve, sprinkle with toasted sesame seeds and sift kinako on top if desired. Cut into 16 squares in a 4 x 4 pattern. These taste great at room temperature or chilled.